COMPARATIVE STABILITY OF ASPIRIN IN CSP TECHNOLOGIES ACTIV-VIALTM AND OWENS- ILLINOIS L-8 PRESCRIPTION VIALS Except where reference is made to the work of others, the work described in this thesis is my own or was done in collaboration with my advisory committee. This thesis does not include proprietary, restricted or classified information. ______________________________ Atresh Tata Certificate of Approval: _________________________ _________________________ Jay Ramapuram Gregory M. Kochak, Chair Assistant Professor Associate Professor Pharmacal Sciences Pharmacal Sciences _________________________ _________________________ Charles R. Breese Daniel L. Parsons Associate Professor Professor Pharmacal Sciences Pharmacal Sciences _________________________ George T. Flowers Interim Dean Graduate School COMPARATIVE STABILITY OF ASPIRIN IN CSP TECHNOLOGIES ACTIV-VIALTM AND OWENS- ILLINOIS L-8 PRESCRIPTION VIALS Atresh Tata A Thesis Submitted to the Graduate Faculty of Auburn University in Partial Fulfillment of the Requirements for the Degree of Master of Science Auburn, Alabama May 10, 2007 iii COMPARATIVE STABILITY OF ASPIRIN IN CSP TECHNOLOGIES ACTIV-VIALTM AND OWENS- ILLINOIS L-8 PRESCRIPTION VIALS Atresh Tata Permission is granted to Auburn University to make copies of this thesis at its discretion, upon the request of individuals or institutions and at their expense. The author reserves all publication rights. _________________________ Signature of Author _________________________ Date: May 10, 2007 iv VITA Atresh Tata, son of Satyanarayana Tata and Subba Rama Lakshmi Tata, was born on August 21st, 1982 in Warangal, Andhra Pradesh, India. He did his schooling at Venkateshwara Convent High School, Hyderabad, India in March 1997 subsequent to which he joined Gangadhar Junior College, Visakhapatnam, to pursue his intermediate education. He then attended Shri Vishnu college of Pharmacy, Andhra University, Bhimavaram, India in 1999 and graduated with a Bachelor of Pharmacy in May 2003. He then entered the graduate program in Pharmaceutics at Auburn University in August 2003. During his studies in the Graduate school he served as a Graduate Teaching and Graduate Research Assistant in the School of Pharmacy. v THESIS ABSTRACT COMPARATIVE STABILITY OF ASPIRIN IN CSP TECHNOLOGIES ACTIV- VIALTM AND OWENS- ILLINOIS L-8 PRESCRIPTION VIALS Atresh Tata Master of Science, May 10, 2007 (B. Pharmacy, Andhra University, 2003) 75 Typed Pages Directed by Gregory M. Kochak The traditional way of drug packaging includes a desiccant pouch along with the drug. The desiccant in the vial helps in preventing the drug degradation due to moisture in surrounding environment. This traditional packaging often proves to be ineffective especially in large vials due to uneven distribution of desiccant. Currently pharmaceutical companies are developing new vials that are made of desiccant embedded polymers to achieve effective drug storage. So it is of utmost importance to study the efficacy of such improved methods. This study presents the results of a comparative study on aspirin stability in CSP Technologies Activ-vial (desiccant embedded polymer vial) with standard Owens-Illinois vials (control). A analytical methods were established and validated to quantify aspirin vi and its primary degradation products using automated high-pressure liquid chromatographic (HPLC) analysis on a silica column. The degradation kinetics of aspirin were evaluated with respect to loss of potency of acetylsalicylic acid and the appearance of three oxidative degradation products of acetylsalicylic acid; salicylic acid, salicylsalicylic acid, and acetylsalicylsalicylic acid under simulated use conditions in a humid environment. The results of this study showed the extent of aspirin degradation was minimal in the time frame studied, although differences were observed in the formation of salicylic acid. Significant suppression of salicylic acid formation was observed in the CSP Technologies Activ-vial when compared to ordinary PET prescription vials. The CSP Technologies Activ-vial is expected to therefore provide an advantage under typical consumer use conditions, particularly in humid geographical regions, for the protection of moisture sensitive pharmaceutical products. vii ACKNOWLEDGEMENTS The author would like to express his heartfelt gratitude to Dr. Gregory M. Kochak for his continued support, guidance and encouragement throughout this period of investigation. The author would like to emphasize the extensive knowledge and genuine concern for students in Dr. Gregory M. Kochak, which benefited him scientifically as well as a person. Thanks are also to Dr. William R. Ravis Dr. Daniel L. Parsons for his invaluable advice and help and the committee members for their useful suggestions. The author is grateful to his parents and sisters for their love, prayers, endless support. Wholehearted thanks to Dr. Prasad N. V. Tata for his support and encouragement, Dr. Basu Sarkar, Umesh Kestur, Dr. Nilimi Viswaprakash for their valuable discussions, Rajesh Guntupalli, Dr. Viswaprakash Nanduri, for their constant motivation and all other friends for their invaluable friendship. The author would also like to express sincere thanks to all of his colleagues in AU Harrison school of Pharmacy Joining group for their assistance and friendship. Finally, the author would like to dedicate this dissertation to the lotus feet of his beloved Lord Vinayaka, Dr. Suryanarayana Somyaji Tata and to his parents (Mrs. Subba Rama Lakshmi Tata and Mr. Satyanaraya Tata), without whose grace, love and forbearance it would not have been possible to learn many things in science as well as in general aspects of life in the course of these years and throughout my life. viii Style manual or journal used International Journal of Pharmaceutics Computer software used Microsoft Office XP for Windows XP ix TABLE OF CONTENTS LIST OF TABLES ??????..?????????.............................................xi LIST OF FIGURES ??????..?????????............................................xii 1 INTRODUCTION ......................................................................................................1 1.1 CONTAINER MOISTURE PERMEATION.......................................................4 1.2 REPACKAGING OF BULK DRUGS.................................................................4 1.3 PHARMACEUTICALLY USED DESICCANTS...............................................7 1.3.1 SILICA GEL ................................................................................................... 8 1.3.2 CLAY DESICCANT....................................................................................... 9 1.3.3 CALCIUM SULFATE .................................................................................... 9 1.3.4 CALCIUM OXIDE....................................................................................... 10 1.4 MOISTURE SENSITIVE DRUGS ...................................................................10 2 EVALUATION OF THE CSP TECHNOLOGIES ACTIV-VIAL ASSOCIATED WITH ASPIRIN STABILITY...................................................................................................12 2.1 DESCRIPTION OF CSP TECHNOLOGIES ACTIV-VIAL.............................12 2.2 PROPOSED ADVANTAGES OF ACTIV- VIAL .............................................15 2.3 POTENTIAL MARKET FOR USE STABILITY OF MOISTURE SENSITIVE DRUGS????????????????????????????..16 2.4 ASPIRIN AS A PROTOTYPICAL MOISTURE SENSITIVE DRUG.............17 x 2.5 OBJECTIVES OF THIS STUDY......................................................................18 3 EXPERIMENTAL........................................................................................................................19 3.1 REAGENTS AND SOURCES ..........................................................................19 3.2 MATERIALS .....................................................................................................19 3.3 PROCEDURES..................................................................................................20 3.4 PREPARATION OF STOCK SOLUTIONS AND CALIBRATION STANDARDS...................................................................................................22 3.5 PREPARATION OF TABLET SAMPLES........................................................24 3.6 CHROMATOGRAPHIC CONDITIONS AND INSTRUMENTATION ..........24 4 RESULTS........................................................................................................................................25 4.1 CHROMATOGRAPHY AND SELECTIVITY.................................................25 4.2 LINEARITY, ACCURACY AND PRECISION................................................25 4.3 STABILITY OF CALIBRATION STANDARDS.............................................26 4.4 STATISTICAL ANALYSIS...............................................................................37 4.5 ASPIRIN ANALYSES.......................................................................................37 4.6 SALICYLIC ACID ANALYSES.......................................................................38 5 CONCLUSIONS...........................................................................................................................45 REFERENCES??????????????????????...?????...45 APPENDICES?????...????????????.??????????...46 6.I REPRESENTATIVE STUDY SAMPLE CHROMATOGRAMS ??... ?.47 6.II TABULATED RESULTS ???.?? ????. ????. ???? 57 xi LIST OF TABLES Table 1: Amount of desiccant needed to absorb at least 6 grams of water vapor at 40% relative humidity at 77? F (25? C)?????????????????.?8 Table 2: List of moisture sensitive drugs????????????????.?.?11 Table 3: Accuracy and precision for the determination of aspirin, salicylic acid and salicylsalicylic acid???????????????????????.34 Table 4: Appendix II - Tabulated Results????????????...?.????..57 Table 5: Appendix II - Tabulated Results??????????????????..58 Table 6: Appendix II - Tabulated Results??????????????????..59 Table 7: Appendix II - Tabulated Results??????????????????..60 Table 8: Appendix II - Tabulated Results?????????????...????...61 xii LIST OF FIGURES Figure 1: Activ- Vial ........................................................................................................ 14 Figure 2: Vials and containers, desiccant sheets and desiccant films. ............................. 16 Figure 3: Water-extracted cross-section of a film illustrating a Polymer / Channel Agent Molecular Sieve desiccants (cube-shaped particles). The desiccants are entrained within interconnecting pathways within a polymer........................ 17 Figure 4: Chromatogram of salicylic acid (SA), RT 6.0 min and salicylsalicylic Acid (SSA), RT 7.1 min. ......................................................................................... 29 Figure 5: Chromatogram of SA, RT 5.8 min and acetylsalicylsalicylic acid (ASA), RT 10.6 min; aspirin standard BA, RT 4.9 min. ................................................... 30 Figure 6: Acetyl salicylic acid calibration curve.............................................................. 31 Figure 7: Salicylic acid calibration curve ........................................................................ 32 Figure 8: Salicylsalicylic acid calibration curve.............................................................. 33 Figure 9: Calibration standards stability of acetyl salicylic acid for a period of 6 hours at the initial concentration, C0 for 150 ?g/mL, 250 ?g/mL and 400 ?g/mL.... 354 Figure 10: Calibration standards stability of salicylic acid from acetylsalicylic acid for a period of 6 hours at the initial concentration, C0 for 150 ?g/mL, 250 ?g/mL and 400 ?g/mL.............................................................................................. 365 xiii Figure 11: Comparison of treatment 1 (T1), 3 (T3) and 5 (T5) for Owen- Illinois PET vials for acetyl salicylic acid. No statistically significant differences were detected between any of the three treatments. .................................................40 Figure 12: Comparison of treatments 2 (T2) and 4 (T4) for CSP technologies activ-vials for acetyl salicylic acid. No statistically significant differences were detected between the two treatments............................................................................. 41 Figure 13: Comparison of treatments 1 (T1), 3 (T3) and 5 (T5) for Owens-Illinois PET vials for salicylic acid. S denotes a statistically significant (p < 0.05) difference from T1, the negative control, and ns denotes no significant difference. ....................................................................................................... 42 Figure 14: Comparison of treatments 2 (T2) and 4 (T4) for CSP technologies activ-vials for salicylic acid. S denotes a statistically significant (p < 0.05) difference from T2, the negative control, and ns denotes no significant difference. ........43 Figure 15: Comparison of treatments 3 (T3) and 4 (T4) for salicylic acid in a simulated use conditions. A relative 40-60% suppression of SA formation was observed for the CSP technologies Activ-Vial. .............................................................. 44 Figure 16: Appendix I - Representative Chromatogram?.???????????..47 Figure 17: Appendix I - Representative Chromatogram???.?????????..48 Figure 18: Appendix I - Representative Chromatogram???.?????????..49 Figure 19: Appendi I - Representative Chromatogram?...???????????..50 Figure 20: Appendix I - Representative Chromatogram?.???????????..51 Figure 21: Appendix I - Representative Chromatogram?.???????????..52 Figure 22: Appendix I - Representative Chromatogram?.???????????..53 xiv Figure 23: Appendix I - Representative Chromatogram?.???????????..54 Figure 24: Appendix I - Representative Chromatogram?.???????????..55 Figure 25: Appendix I - Representative Chromatogram???.?????????..56 1 1 INTRODUCTION The term ?stability,? with respect to a drug dosage form, refers to the chemical and physical integrity of the dosage unit and, when appropriate, the ability of the dosage unit to maintain protection against microbiological contamination. The self life is the time lapse from initial preparation to the specified expiration date. The stability parameters of a drug dosage form can be influenced by environmental conditions like temperature, light, air and humidity. Pharmacopoeial articles should include required storage conditions on their labeling under which the expiration date shall apply. Stability studies on active substances and packaged dosage forms are conducted by means of ?real time,? long-term tests at specific temperatures and relative humidity. Labeling and packaged active substance or dosage form should reflect the effects of temperature, relative humidity, air and light on its stability1. Each ingredient, whether therapeutically active or pharmaceutically necessary, can affect the stability of drug substances and dosage forms. The primary environmental factors that may reduce the stability include exposure to adverse temperature, light, humidity, oxygen and carbon dioxide. Major factors that influence drug stability include particle size, solvent system composition, compatibility of anions and cations, solution ionic strength, primary container, specific chemical additives, molecular binding temperature, relative humidity and diffusion of drugs and excipients. In dosage forms these reactions usually cause loss of active drug content and 2 do not provide obvious visual and olfactory evidence of their occurrence. The reactions are hydrolysis, epimerization, decarboxylation, dehydration, oxidation and photochemical decomposition. Many pharmacopoeial articles which undergo the above mentioned reactions require the greatest attention to the containers in which they are stored or maintained even for short periods of time. The stability of drug products needs to be evaluated over time in the same container-closure system in which the drug product is marketed. In some cases, accelerated stability studies can be used to support tentative expiration dates in the event that full shelf life studies are not available. When a drug manufacturer changes the packaging of a drug product (e.g., from a bottle to unit-dose), stability testing must be performed on the product in its new packaging, and expiration dating must reflect the results of the new stability testing. Specific light resistant containers meet the requirements for light transmission. Criteria for Acceptable Levels of Stability Type of stability Conditions maintained throughout the shelf-life of the drug product. Chemical Each active ingredient retains its chemical integrity and labeled potency, within specified limits. 3 Physical The original physical properties, including appearance, palatability, uniformity, dissolution, and suspendability are retained. Microbiological Sterility or resistance to microbial growth is retained according to specified requirements. Antimicrobial agents that are present retain effectiveness within specified limits. Therapeutic The therapeutic effect remains unchanged. Toxicological No significant increase in toxicity occurs. The design of a stability study varies from product to product. First formulators determine the effects of temperature, light, air, pH, moisture, trace metals, and commonly used excipients or solvents on the active ingredient. At appropriate time intervals, samples of the product are assayed for potency by use of a stability indicating method, observed physical changes, and where applicable, tested for sterility and/or for resistance to microbial growth and for toxicity and bioavailability2. 4 1.1 Container Moisture Permeation Tests are provided to determine the moisture permeability of containers utilized for drugs being dispensed on prescription. The term ?container? refers to the entire system comprising, usually, the container itself, the liner (if used), the closure in the case of multiple unit containers, and the lidding and blister in case of single unit and multiple unit containers. If the containers are lined with desiccants then permeation of moisture or any extraneous material will be difficult. The desiccant material can be seamlessly integrated into primary packaging. This eliminates the costly step of inserting secondary components into a package and eliminates the risk that the consumer will discard the desiccant material. The rate of moisture permeability is usually calculated in mg per day per liter for multiple unit containers for capsules and tablets3. 1.2 Repackaging of Bulk Drugs Unit dose packaging systems are currently widespread in health care. Some unit dose containers are available directly from manufacturers and repackagers and some drugs are packaged into unit dose by hospital/community pharmacies or shared service establishments. A unit dose package makes the administration of drugs more convenient and less susceptible to errors (such as administering too much or too little of the drug at one time). Repackaging previously dispensed drugs into unit dose containers may be inappropriate under the FDA?s compliance policy guide for repackaging and return of used 5 medications, as well as state laws that regulate the practice of pharmacy. Moreover, such repackaging raises liability concerns for pharmacies. In order to repackage a prescription drug, a repackaging entity, including a pharmacy, must have specific information, and such information must appear on the label of the unit dose container. Without the specific information, a unit dose package of a prescription drug is considered to be misbranded under CPG 7132b.10 (FDA, Office of regulatory affairs): The information required by law is, 1. Name of the drug and quantity of the active ingredient per dosage unit; 2. Expiration date; 3. Lot or control Number; 4. Name and place of business of the manufacturer, packer, or distributor; and 5. Required statements regarding refrigeration or bearing on the special characteristics of the drug. CPG 7132.13 clarifies that repackagers are not required to separately undertake testing procedures associated with good manufacturing practices, but only if the following is true: 1. The incoming bulk containers of finished dosage form drug products are received intact, in undamaged container which are completely and properly labeled as received, and there is no reason to suspect that they have been subjected to improper storage or transit conditions prior to receipt; and 6 2. The repackaged containers are labeled with the same substantive labeling declarations (e.g., identity, strength, and directions for use) concerning the properties and use of the drug product which are consistent with the labeling on the incoming bulk containers. No action will be initiated against any unit dose repackaging firm, including shared services, or drug product in a unit dose container meeting all other conditions of FDA?s repackaging requirements solely on the basis of the failure of the repackaging firm to have stability studies supporting the expiration dates used, provided: 1. The unit dose container complies with the class A or class B standard described in the twentieth edition of the United States Pharmacopoeia, general tests, single- unit containers and unit-dose containers for capsules and tablets (page 955). 2. The expiration date does not exceed six months; and 3. The six month expiration period does not exceed 25 percent of the remaining time between the date of repackaging and expiration date shown on the original manufacture?s bulk container of the drug repackaged, and the bulk container has not been previously opened. This policy only applies to solid and liquid oral dosage forms in unit dose containers. This policy does not apply to antibiotics or to nitroglycerin sublingual tablets which are 7 known to have stability problems that preclude them from being repackaged. The question remains whether this policy applies to other moisture sensitive drugs4, 5. 1.3 Pharmaceutically Used Desiccants A desiccant is a substance with very hygroscopic properties, meaning it will adsorb water vapor from the air surrounding it. A number of different substances are capable of doing this, but only a relative few are of practical use and fewer still are going to be readily available. Before elaborating on the different types that might be useful for any given purposes it's necessary to explain how to choose a desiccant. The U.S. military has done much of the best research on the use of desiccants in packaging and have largely set the standards by which they are judged. Each type of desiccant has temperature and humidity ranges where it performs best and particular physical and chemical characteristics that may need to be considered in relation to what you propose to do with them. The most applicable standard for home food storage defines a unit of desiccant as the amount of desiccant that will adsorb at least 6 grams of water vapor at 40% relative humidity at 77? F (25? C). The following table provides the adsorptive capacity of some commonly used desiccants (Table 1) 6. 8 Table 1: Amount of desiccant needed to absorb at least 6 grams of water vapor at 40% relative humidity at 77? F (25? C). Desiccant Mass (grams) Silica Gel 15 Indicating Silica Gel 75 Montmorillonite Clay 24 Calcium Oxide (quicklime) 22 Calcium Sulfate (gypsum, Drierite) 60 Wood 43 1.3.1 Silica Gel The most commonly known and used desiccant is silica gel which is a form of silica dioxide (SiO2), a naturally occurring mineral. It will work from below freezing to past the boiling point of water, but performs best at room temperatures (70-90 ?F) and high humidity (60-90%). Its performance begins to drop off over 100? F, but retains activity until approximately 220? F. It will lower the relative humidity in a container to around 40% at any temperature in its range until it is saturated. Silica gel will absorb up to 40% of its weight in moisture. Some forms are approved by the Food and Drug Administration (FDA) for direct food use. It recharges easily and does not swell in size as it adsorbs moisture6. 9 1.3.2 Clay Desiccant Clay desiccant is fairly common in commercial and industrial use. The primary reason for this seems to be that it is inexpensive compared to any other form of desiccant. The material is montmorillonite clay, composed primarily of magnesium aluminum silicate, a naturally occurring mineral. After mining it is purified, reduced to granules and subjected to a controlled dehydration process to increase its sorbent porosity. It recharges easily and does not swell as it adsorbs water vapor. It works well at low and room temperatures, but has a rather low ceiling temperature. At 120? F it will begin to desorbs or shed the moisture it has adsorbed. This is an important consideration for storage in hot areas. Subject to a degree of variability for being a natural material, clay desiccant will adsorb approximately 25% of its weight in water vapor at 77? F and 40% relative humidity6. 1.3.3 Calcium Sulfate Also known as the mineral gypsum and commercially as Drierite, calcium sulfate is another naturally occurring mineral. It is produced by the controlled dehydration of gypsum (CaSO4). It is chemically stable and does not readily release its adsorbed moisture. It has a low adsorbency capacity, only approximately 10% of it weight. It can be regenerated, but not easily6. 10 1.3.4 Calcium Oxide Also known as "quicklime" or "unslaked lime", calcium oxide is a slow, but strong adsorbent. It is efficient at low humidity?s and can drop moisture vapor to below 10% relative humidity. Quicklime is caustic and must be carefully handled, particularly with regards to dust inhalation and exposure to skin and eyes. It expands as it soaks up water vapor and this must be taken into account when packaging it. It will adsorb up to about 28% of its weight in moisture, but does it slowly over a period of several days rather than a matter of hours like other desiccants. It is most effective when used in high humidity environment where a very low humidity level is desired. It will release a fair amount of heat if exposed to directly to moisture or extreme humidity?s 6. 1.4 Moisture Sensitive Drugs The pharmacopoeial requirements for the use of specified containers apply also to articles as packaged by the pharmacist or other dispenser, unless otherwise indicated in the individual monograph. Moisture sensitive drugs are to be stored in tight containers. Tight containers protect the contents from extraneous liquid, solids, or vapors, from the loss of the article and from efflorescence, deliquescence, or evaporation under the ordinary or customary conditions of handling, shipment, storage and distribution, the containers must be capable of tight re-closure. Pharmacopoeial standards, however, do not address typical consumer use conditions. The following table represents some of the moisture sensitive drugs7 11 Table 2: List of moisture sensitive drugs Albendazole Guanadrel Oxytetracycline Alprazolam Guanfacine Penicillamine Aminophylline Haloperidol Phenytoin Sodium Amoxicillin Hydralazine Hydrochloride Piroxicam Aspirin Hydrocodone Bitartrate Phensuximide Bendroflumethiazide Hydroflumethiazide Promethazine Hydrochloride Bethanechol Hydrochloride Hydromorphone Hydrochloride Pyridostigmine Bromide Biperidine Hydrochloride Imipramine Hydrochloride Quinidine Sulfate Bromocriptine Mesylate Iopanoic Acid Quinine Sulfate Buspirone Hydrochloride Ipodate Sodium Ranitidine Captopril Isotretinion Reserpine Chloramphenicol Isoxsuprine Hydrochloride Riboflavin Carbamazepine Kanamycin Rifampin Cyclosporine Labetalol Hydrochloride Ritodrine Hydrochloride Cyclophosphamide Levodopa Scopolamine Hydrochloride Desipramine Hydrochloride Lincomycin Hydrochloride Secobarbital Sodium Diazepam Liothyronin Sodium Simvastatin Diclefenac Sodium Lorazepam Spironolactone Digitalis Mazindol Stanozolol Disulfuram Mesalamine Tetracycline Hydrochloride Ephedrine Sulfate Methsuximide Thiabendazole Ergocalciferol Minoxidil Trimethoprim Ethosuximide Mitotane Trichlormethiazide Ethotoin Neostigmine Bromide Thiamine Hydrochloride Flucytosine Niacinamide Valporic Acid Fluoxetine Nifedipine Vancomycin Hydrochloride Fluphenazine Hydrochloride Nitroglycerin Verapamil Hydrochloride Flurazepam Hydrochloride Nystatin Vitamin A Furazolidone Oxandrolone Vitamin E Glipizide Oxtriphylline Warfarin Sodium Greseofulvin Oxybutynin Chloride Zalcitabine Guanabenz Oxycodone Hydrochloride Zidovudine 12 2 EVALUATION OF THE CSP TECHNOLOGIES ACTIV- VIAL ASSOCIATED WITH ASPIRIN STABILITY 2.1 Description of CSP Technologies Activ-Vial CSP Technologies (Auburn AL) M-3006-47 Activ-Vial TM. The Activ-Vial is a two-shot flip top vial. The outer vial is molded polypropylene using a process which allows closure of the vial with a polypropylene cap in the mold. The body and cap are cooled together creating a tight seal. The vial body contains an over-molded inner sleeve containing 8.0 grams of porous (4?) alumina silicate and manufactured using a patented process incorporating a base polymer and channeling agent. Both vials have a volume of approximately 31 cc. The Activ-Pak polymer blend is made up of three components ? the polymer, a channeling agent, and an active component such as desiccant ? that allows for the creation of stable, co-continuous, interpenetrating ? or ?web-like? ? channels. These channels facilitate transport, via diffusion, of substances throughout the polymer. The resulting polymer blend responds to external signals and stimuli in a pre-programmed fashion, activating the desired environmental control, whether it is absorption, release, transport or activation of substances through the channels. This process 13 removes the barrier characteristic associated with plastic, while retaining the characteristic of structure. Activ-Pak offers functionality and flexibility in plastics. Many different materials can be incorporated into these polymer blends, enabling you to provide a controlled environment within product packaging. Formulators can reproducibly and predictably control the rate and duration of the desired activity8. 14 Figure 1: Activ- Vial 15 Applications for Activ- Pak Technology 2.2 Proposed Advantages of Activ- Vial These are some of the advantages of Activ- Vial 1. The Activ-Vial offers control and reproducibility of the rate and duration of humidity control required to optimize the performance of the products. 2. It offers an air-tight and leak-proof environment to maintain product integrity and prolong shelf-life. 3. The unique single-mold vial and closure system vial allows the user to open and close with one hand and requires minimal pressure to seal. 4. The cost-effective one-piece design enhances the inventory control and production efficiencies, eliminates mismatches between bottles and caps, and removes cross contamination issues. 5. It provides greater moisture adsorptive capacity than ordinary silica gel8. Moisture absorption CO2/O2/ethylene/formaldehyde absorption Biocide release Flavor/odor/fragrance Dry sterilization Absorption or release 16 Figure 2: Vials and containers, desiccant sheets and desiccant films. 2.3 Potential Market for Use Stability of Moisture Sensitive Drugs It is an industry axiom that the number one threat to pharmaceutical stability is moisture and its effect on increasing molecular mobility. As such, incorporating desiccants into packaging for moisture control has been a long-established practice. An array of new solid-dose drug formulations, however, can reasonably be described as unstable, and therefore require special protection beyond the ?traditional? moisture-controlling desiccant or oxygen scavenger. A number of molecules that are particularly moisture- sensitive or highly-oxidative have been shelved by drug manufacturers over the past 10 to 20 years because they could not be stabilized through reformulation and/or traditional 17 packaging protection options. Thus, many promising drugs have been stopped in the pipeline for years. Figure 3: Water-extracted cross-section of a film illustrating a Polymer / Channel Agent / Molecular Sieve desiccants (cube-shaped particles). The desiccants are entrained within interconnecting pathways within a polymer. 2.4 Aspirin as a Prototypical Moisture Sensitive Drug Aspirin, the prototype of the salicylates, is a nonsteroidal anti-inflammatory agent. Aspirin is the salicylate ester of acetic acid. In vivo, the drug rapidly hydrolyzes to salicylate and acetate. Aspirin occurs as white crystals, which are usually tabular or needle-like, or as a white, crystalline powder. Aspirin is stable in dry air. However, in moist air or in aqueous or hydro alcoholic solutions, the drug hydrolyzes to salicylate and acetate and emits a strong vinegar-like odor; the rate of hydrolysis is increased by heat and is pH dependent. In aqueous solutions, aspirin is most stable at a pH of 2?3, less 18 stable at a pH of 4?8, and least stable at a pH less than 2 or greater than 8. In a saturated aqueous solution at a pH of 5?7, aspirin is almost completely hydrolyzed within 1 week at 25?C. Manufacturers labeling suggests that aspirin extra-strength (Anacin?) tablets should be stored at 20?25?C and protected from moisture. Aspirin (Bayer products, excluding Alka-Seltzer? products) tablets or caplets should be stored at room temperature; high humidity and excessive heat (40?C) should be avoided. 2.5 Objectives of this Study The purpose of this study is to compare the stability of aspirin in CSP Technologies Acitv- vials containing an over- molded desiccant polymer and in standard Owens- Illinois polyethylene prescription vials when exposed to simulated consumer use conditions in a high humidity environment. The degradation kinetics of aspirin was evaluated with respect to loss of potency of acetylsalicylic acid and formation of salicylic acid, salicylsalicylic acid, and acetylsalicylsalicylic acid. A stability- indicating assay for the analyses of aspirin and its degradation products, salicylic acid and salicylsalicylic acid was established and validated9. 19 3 EXPERIMENTAL 3.1 Reagents and sources Chloroform (A.C.S. grade), n-heptane (HPLC grade), and acetic acid (glacial, A.C.S. PLUS grade) are used as chromatographic solvents (Fisher Scientific/Acros Organics, Pittsburgh, PA). Chloroform and n-heptane are kept dry by the addition of sodium calcium aluminosilicate hydrate dessicant sponges (Fisher). Analytical standards are prepared from acetylsalicylic acid (ASA), purity 99% (Acros), salicylic acid (SA), purity >99% (Acros), salicylsalicylic acid (SSA), purity 99% (Acros), and benzoic acid (BA), purity >99% (J. T. Baker Chemical Co., Phillipsburg, NJ). Disintegrated tablets are filtered using disposable solvent-resistant PTFE filter units (Fisher) and standard polypropylene syringes. 3.2 Materials Owen-Illinois (Toledo OH) L-8 polyethylene prescription vials with SL-26 Screw-Loc closures designated as USP 671 tightly closed (T) and light resistant (LR). 20 Commercial Bayer Aspirin (Bayer Healthcare LLC, Consumer care division, Morristown NJ) 325 mg coated tablets (lot no. 294414K, expiration date 7/06). Inert ingredients are corn starch, hypromellose, powdered cellulose and triacetin. 3.3 Procedures Bayer Aspirin 325 mg tablets were placed in Owens-Illinois PET prescription vials or CSP Technologies M-3006-47 Activ-Vials. Owens-Illinois vials were closed with Screw- Loc child resistant caps when appropriate. Five treatments were tested as follows: Treatment 1: Owens-Illinois vial containing aspirin tablets and closed with a Screw-Loc cap. The prescription vial system remained closed throughout the duration of the study with the exception of the time required to remove tablets for sample collection. This treatment was a negative control for the Owens- Illinois vial system. Treatment 2: CSP Technologies M-3006-47 Activ-Vial containing aspirin tablets and closed with its attached cap. The vial system remained closed throughout the duration of the study with the exception of the time required to remove tablets for sample collection. This treatment was a negative control for the CSP technologies vial system. Treatment 3: Owens-Illinois vial containing aspirin tablets and closed with a Screw-Loc cap. The prescription vial system was periodically opened three times-a- 21 day for duration of 1.0 minute each exposure and 3.0 minutes per day total exposure to environmental conditions. This treatment was designed to mimic typical consumer use conditions. Treatment 4: CSP Technologies M-3006-47 Activ-Vial containing aspirin tablets and closed with its attached cap. The vial system was periodically opened three times-a-day for duration of 1.0 minute each exposure and 3.0 minutes per day total exposure to environmental conditions. This treatment was designed to mimic typical consumer use conditions. Treatment 5: Owens-Illinois vial containing aspirin tablets without a closure. This vial represented a positive control with 100% exposure to environmental conditions. Each treatment was exposed to controlled environmental conditions in a stability (temperature/humidity) chamber at 30?C and 80% relative humidity. All vials remained in the chamber throughout the duration of study. The total duration of exposure of the aspirin tablets subject to cyclic opening and closing was 360 min or 0.208% of the total study period. Treatments 1, 2, and 5 were exposed to environmental conditions of 40?C and 75% relative humidity for an additional 30 days following completion of the initial treatment protocol for 120 days. 22 Six tablets were sampled from each treatment vial at 0, 30, 60, 90, and 120 days. For treatments 1, 2, and 5 only three tablets were removed for sampling at 120 days and the remaining tablets retained for further exposure to 40?C and 75% relative humidity for an additional 30 days. Sampled tablets were sealed in moisture retardant metallized polyester barrier pouches until analyzed. 3.4 Preparation of stock solutions and calibration standards ASA and SSA stock solutions were freshly prepared on the day of use. A stock solution of aspirin was prepared by accurately weighing 400 mg of ASA and adding it to a 100- mL volumetric flask. The ASA was dissolved in solvent containing 5% acetic acid, 47.5% chloroform and 47.5% n-heptane (v/v/v) resulting in a final concentration of 4.0 mg/mL. Stock solutions of salicylic acid and salicylsalicylic acid are separately prepared by accurately weighing 200 mg of SA and 100 mg of SSA, respectively, and adding to 100-mL volumetric flasks. The SA and SSA are dissolved in solvent containing 5% acetic acid, 47.5% chloroform and 47.5% n-heptane (v/v/v) resulting in a final concentration of 2.0 mg/mL and 1.0 mg/mL, respectively. For SA, serial dilutions were prepared by diluting 10.0 ml of the 2.0 mg/mL primary stock solution to 100 mL with 5% acetic acid, 47.5% chloroform and 47.5% n-heptane in a 100-mL volumetric flask, and diluting 1.0 mL of this solution to 10.0 mL with the same solvents resulting in a final concentration of 2.0 ?g/mL. For SSA, secondary serial dilutions are prepared by diluting 10.0 mL of the 1.0 mg/mL primary stock solution to 100 mL with 5% acetic acid, 47.5% chloroform and 47.5% n-heptane in a 100-mL volumetric flask, and diluting 1.0 mL of 23 this solution to 10.0 mL with the same solvents resulting in a final concentration of 10.0 ?g/mL. A stock solution of benzoic acid was prepared by accurately weighing 400 mg BA, adding to a 100-mL volumetric flask, and dissolving in 5% acetic acid, 47.5% chloroform and 47.5% n-heptane (v/v/v) resulting in a final concentration of 4.0 mg/mL. Benzoic acid was used as a competitive inhibitor of SA and SSA adsorption on glass10-13. Calibration standards of ASA are prepared by diluting 500 ?L, 406 ?L, 313 ?L, and 188 ?L of the 4.0 mg/mL ASA stock solution to 10.0 mL, respectively, with 50% chloroform and 50% n-heptane in 10-mL volumetric flasks. The final concentrations of the ASA calibration standards are 200, 163, 125 and 75 ?g/mL, respectively. Calibration standards for SA and SSA containing the internal standard are prepared by adding 7.5 mL of the 2.0 ?g/mL SA stock solution, 5.0 mL of the 10.0 ?g/mL SSA stock solution, and 500 ?L of the 4.0 mg/mL BA stock solution to a 10-mL volumetric flask and diluting with 50% chloroform and 50% n-heptane. Similarly standards containing, 5 mL of SA stock, 2.0 mL of SSA stock, and 500 ?L of BA stock; 2.5 mL of SA stock, 1.0 mL of SSA stock, and 500 ?L of BA stock; and, 1 mL of SA stock, 0.5 mL of SSA stock, and 500 ?L of BA stock and 500 ?L of SA stock and 500 ?L of BA stock are prepared. The resulting final concentrations for these calibration standards are 1.5 ?g/mL SA and 5 ?g/mL SSA, 1.0 ?g/mL SA and 2 ?g/mL SSA, 0.5 ?g/mL SA and 1 ?g/mL SSA, and 0.2 ?g/mL SA and 0.5 ?g/mL SSA and 0.1 ?g/mL of SA respectively. The final BA concentration 200 ?g/mL for all calibration standards. 24 3.5 Preparation of tablet samples One (1) tablet of aspirin with an initial labeled content of 325 mg aspirin was added to a 100-mL volumetric flask. Solvent containing 5% acetic acid, 47.5% chloroform and 47.5% n-heptane (v/v/v) was added to the flask and brought to volume. The sample was sonicated for 10 min to aid in disintegration of the tablet. An aliquot of the resulting solution containing particulate matter was filtered through an inert PTFE filter membrane using a polypropylene syringe, and 0.5 mL transferred to a 10-mL volumetric flask. An aliquot of 500 ?L of the 4.0 mg/mL BA stock solution was added to the flask and diluted with solvent containing 50% chloroform and 50% n-heptane14, 15. 3.6 Chromatographic conditions and instrumentation The chromatographic system consists of Varian (Walnut Creek, CA) ProStar 210 solvent delivery pumps, a ProStar 320 variable-wavelength UV/Vis detector, and ProStar 400 auto sample. Data collection and processing use Star Chromatography Data Acquisition v5 software and a PC computer. Chromatography was carried out in the normal-phase mode. The stationary phase was Microsorb-MV 5 ?m silica, 25 cm x 4.6 mm i.d. column (Varian). The mobile phase was 4.4% acetic acid (glacial), 76.3% n-heptane and 19.3% chloroform delivered at a flow rate of 1.0 mL/min. Column temperature was ambient. The detector wavelength for all analytes was 292 nm. The injection volume was 40 ?L. 25 4 RESULTS 4.1 Chromatography and selectivity Typical chromatograms obtained from spiked standards are illustrated in Figures 4 and 5. Figure 4 shows SA with a retention time of 6.0 min and SSA with a retention time of 7.1 min. Salicylic acid and salicylsalicylic acid can be quantified using a single calibration curve. A separate calibration curve is required to quantify aspirin since both analytical standards and aspirin tablets contain trace levels of salicylic acid (Figure 5). The retention time of ASA was 10.6 min and SA was 5.8 min. Small variations in retention times were observed. Blank samples (injected mobile phase) showed no detectable levels of any analyte. The retention time of benzoic acid was 4.9 min. Shifting the detection absorbance wavelength to 292 nm results in a large increase in BA absorbance and detector response. 4.2 Linearity, accuracy and precision Calibration curves were fit by linear least-squares regression. The calibration curve for ASA, SA, and SSA were based on peak area. ASA concentrations were linear in the calibration range of 75 to 200 ?g/mL (Fig. 6). The corresponding r value was 0.9942. SA concentrations were linear in the calibration range 0.1 to 2.0 ?g/mL (Fig. 7). The corresponding r value was 0.9980. SSA concentrations were linear in the calibration 26 range of 0.50 to 5.0 ?g/mL (Fig. 8) the corresponding r value was 0.9948. Extended concentration ranges for all analytes exhibited nonlinear trends, which were determined to result from adsorption of analytes to glassware and probably nonlinear on-column silica adsorption as well. Salicylic acid was found to be the most severely adsorbing analyte. The addition of 5% acetic acid to stock solutions and benzoic acid with a concentration of 200 ?g/mL minimized glassware adsorption by competitive binding but did not eliminate all nonlinear trends. In all cases, the linear ranges of analytes were limited. Extreme caution was required when changing analyte concentration ranges as well as revalidation for the modified ranges. The accuracy and precision of ASA, SA and SSA are provided in Table 3. The accuracy of ASA analyses was within 2% of the nominal values for all concentration levels. Reproducibility was < 6% relative standard deviation (RSD) for all levels. The accuracy of SA analyses was within 7% of the nominal values for levels of 0.2 to 1.5 ?g/mL and 110% at the lowest calibration level of 0.1 ?g/mL. Reproducibility was <12% RSD for concentration levels of 0.2 to 1.5 ?g/mL, and 40% at the lowest calibration level of 0.1 ?g/mL. The accuracy of SSA analyses was within 3% of the nominal values for levels of 0.5, 1, 5 ?g/mL and <13% for calibration level of 2 ?g/mL. Reproducibility was <8% RSD for all levels. 4.3 Stability of calibration standards The stability of solutions of ASA in 5% acetic acid, 47.5% chloroform and 47.5% n- heptane (v/v/v) were evaluated for quantifiable loss of ASA and generation of SA. 27 Freshly prepared solutions at initial concentrations of 150, 250 and 400 ?g/mL ASA were analyzed at timed intervals. Solutions were left undisturbed at ambient temperature (20- 23?C) on the bench top. No detectable degradation in ASA peak area was observed at all concentration levels (Fig. 9), however, increased levels of SA were detectable and quantified over a 6-hour period (Fig. 10). At an initial (C0) ASA concentration of 150 ?g/mL, SA showed stable kinetics. SA peak areas were uncorrelated with time, and no detectable slope in the curve was determined. At an initial ASA concentration of 250 ?g/mL a significant time- correlation was observed. At 6 hr, a relative increase of 41% in SA peak area was observed. At an initial ASA concentration of 400 ?g/mL, SA peak areas were correlated with time and showed 114% increase in peak area at 6 hr. These results indicate that stock solutions of ASA and extracted tablet solutions must be prepared at the time of analysis and diluted to appropriate concentrations as rapidly as feasible. To insure accurate calibration of SA concentration levels, separate calibration curves are required for SA and ASA. The highest level ASA calibration standard was specified in this method at 200 ?g/mL. Based on the methodology presented in this report, a 325 mg aspirin tablet would result in a 162.5 ?g/mL solution of ASA after sample processing at time 0 hr. Although the relative increases in SA levels at 6 hr represent the conversion of ASA to SA, initial SA levels in raw material, analytical standards or tablets, are present as trace quantities. Nevertheless, strict control of processing time and dilution levels was required to insure that artifactual degradation of ASA is minimized, and that assayed values are actually representative of test conditions. 28 29 Figure 4: Chromatogram of salicylic acid (SA), RT 6.0 min and salicylsalicylic Acid (SSA), RT 7.1 min. 30 Figure 5: Chromatogram of SA, RT 5.8 min and acetylsalicylsalicylic acid (ASA), RT 10.6 min; aspirin standard BA, RT 4.9 min. 31 y = 8268.5x + 95309 0 0.5 1 1.5 2 0 50 100 150 200 250 ASA Conc (?g/mL) Pe ak A re a ( Ar bi tra ry un its in m ill io ns ) Figure 6: Acetyl salicylic acid calibration curve. 32 y = 29585x + 2642.8 0 10 20 30 40 50 0.0 0.5 1.0 1.5 2.0 SA Conc (?g/mL) Pe ak A re a ( Ar bi tra ry u ni ts in th ou sa nd s) Figure 7: Salicylic acid calibration curve. 33 y = 30316x - 1291.2 0 50 100 150 200 0.0 2.0 4.0 6.0 SSA Conc (?g/mL) Pe ak A re a ( Ar bi tra ry u ni ts in th ou sa nd s) Figure 8: Salicylsalicylic acid calibration curve. 34 Table 3: Accuracy and precision for the determination of aspirin, salicylic acid and salicylsalicylic acid. Analyte Calibration Level N Assay Mean Accuracy RSD (ug/mL) (ug/mL) % % Aspirin 75 9 73.7 98.3 2.82 125 9 126.1 100.9 5.19 162.5 9 164.6 101.3 2.75 200 9 198.1 99.1 2.87 Salicylic acid 0.1 5 0.11 110.0 39.74 0.2 5 0.19 93.4 11.47 0.5 5 0.49 97.5 3.38 1 5 1.03 103.1 3.96 1.5 5 1.48 99.0 1.32 Salicylsalicylic acid 0.5 7 0.51 101.2 2.49 1 7 1.03 102.9 7.48 2 7 1.95 97.6 3.39 5 7 5.01 100.3 7.24 RSD, relative standard deviation N, number of replicates 35 Figure 9: Calibration standards stability of acetyl salicylic acid for a period of 6 hours at the initial concentration, C0, for 150 ?g/mL, 250 ?g/mL and 400 ?g/mL. 0 100 200 300 400 500 600 700 800 900 0 2 4 6 8 Time (hr) C0 = 150 ?g/mL C0 = 250 ?g/mL C0 = 400 ?g/mL AS A Pe ak A re a ( Ar bit ra ry un its in th ou sa nd s) 36 Figure 10: Calibration standards stability of salicylic acid from acetylsalicylic acid for a period of 6 hours at the initial concentration, C0 for 150 ?g/mL, 250 ?g/mL and 400 ?g/mL. R 2 = 0.0911 R 2 = 0.9257 R 2 = 0.9894 0 1 2 3 4 5 6 7 8 9 0 2 4 6 8 Time (hr) C0 = 150 ?g/mL C0 = 250 ?g/mL C0 = 400 ?g/mL SA P ea k A re a ( Ar bit ra ry un its in th ou sa nd s) 37 4.4 Statistical Analysis Comparative statistics were analyzed by one-way ANOVA with treatment or treatment within time period used as factors. In some cases, Treatments 1 and 2 (negative controls) were considered reference standards for relative comparisons of time-related trends. These tests used a minimum 5% level of significance to determine comparative differences, and all reported P values are two sided. Other statistical analyses include least-squares regression analysis and correlation analysis. Nominal statistics include the average and standard deviation (SD). 4.5 Aspirin Analyses No time related trends were observed associated with the degradation of ASA for treatments utilizing Owens-Illinois PET prescription vials (Fig.11) or CSP Technologies Activ-Vial (Fig. 12). There was no statistical distinction (p = 0.51) between any of the three treatments employing the Owens-Illinois vials. The correlation coefficient (R2) corresponding to the relationship between ASA content per tablet and duration of exposure was 0.0004 which was not statistical distinguishable (p = 0.87) from 0, that is, no correlation. In addition, there was no statistical distinction (p = 0.24) between the two treatments employing the CSP Technologies Activ-Vial. The R2 value corresponding to the relationship between ASA content per tablet and duration of exposure was 0.0018 which was not significant (p = 0.77). The mean (SD) aspirin content corresponding to Treatments 1, 3 and 5 was 312.9 (12.97) mg per tablet, or 96.3% of the labeled content. The mean (SD) aspirin content corresponding to Treatments 2 and 4 was 313.8 (17.10) 38 mg per tablet, or 96.5% of the labeled content. Both of these values are within FDA regulatory specifications of ? 5% for labeled content of manufactured pharmaceuticals tablets. 4.6 Salicylic Acid Analyses There was no significant time-related trend associated with Treatment 1 (Fig. 13). The R2 value corresponding to the relationship between SA content per tablet and duration of exposure was 0.0010 which was not significant (p = 0.88). For treatment 2 (Fig. 14), the SA content per tablet was negatively correlated (R2=0.2719) with the duration of exposure to environmental conditions. This relationship was statistically significant (p< 0.01). Bayer aspirin tablets contained as average 0.25 mg of SA per tablet on day 0, prior to exposure to any of the test conditions. This initial level of SA reflects unavoidable contamination of aspirin raw material at the time of manufacturing and is well within compendial tolerance of 3.0% for coated tablets or 0.1% for aspirin raw material relative to ASA content. Although quantitative analysis of SA concentrations corresponding with Treatments 1 and 2 resulted in levels of 0.1 to 0.2 ?g/mL at all sampling times, levels near the quantifiable limit of the assay, the significant reduction in initial SA content per tablet resulting from Treatment 2 may indicate some leaching by the vial. The lack of a significant time-related trend for Treatment 1 does not necessarily preclude leaching by the Owens-Illinois vials since accumulation of SA by degradation due to moisture ingress may offset any observable difference in SA levels relative to the 39 initial (Day 0) SA content. In either case, however, aspirin is stable for at least 120 days to significant degradation which may result from moisture ingress in the closed Owens- Illinois or CSP technologies vial systems. Treatment 3, 4, and 5 all showed time-related accumulation of SA. Each of these treatments was associated with either continuous exposure to moisture or exposure to trapped moisture due to intermittent opening and closing of vials. No tablet showed accumulation of SA in excess 1 mg or 0.4% of labeled SA equivalents within 120 days for any of these treatments. This level of degradation is consistent with ASA content findings since ? 0.4% degradation is well within distinguishable statistical limits of ASA content variability. Statistically distinguishable (p < 0.05) accumulation of SA was observed beginning at 60 days for the open Owens-Illinois vial (Treatment 5) and at 90 days for the periodically open CSP Technologies Activ-Vial (Treatment 4). Comparative analysis of the Owens-Illinois PET prescription vials (Treatment 3) and CSP Technologies Activ-Vial (Treatment 4) showed significant (p < 0.001) suppression of SA formation beginning at 60 days (Fig. 15). The relative suppression of SA formation was 58% at 60 days, 60% at 90 days, and 41% at 120 days. Although neither vial system completely eliminated the formation of SA when exposed to simulated use conditions at 30?C and 80% RH and compared to ingress moisture degradation only, the extent of protection provided by the Activ-Vial system was substantial. These results demonstrate the utility of the CSP Technologies Activ-Vial to reduce humidity within the vial under simulated conditions for a period of 120 days. 40 150 200 250 300 350 0 50 100 150 Time (days) AS A (m g/ tab let ) T1 T3 T5 Figure 11: Comparison of treatment 1 (T1), 3 (T3) and 5 (T5) for Owen- Illinois PET vials for acetyl salicylic acid. No statistically significant differences were detected between any of the three treatments. 41 150 200 250 300 350 0 50 100 150 Time (days) AS A (m g/ tab let ) T2 T4 Figure 12: Comparison of treatments 2 (T2) and 4 (T4) for CSP technologies activ-vials for acetyl salicylic acid. No statistically significant differences were detected between the two treatments. 42 0 2 4 6 8 10 12 0 30 60 90 120 Time (days) SA (m gx 10 1 / tab let ) T1 T3 T5 ns, ns ns s s s s Figure 13: Comparison of treatments 1 (T1), 3 (T3) and 5 (T5) for Owens-Illinois PET vials for salicylic acid. S denotes a statistically significant (p < 0.05) difference from T1, the negative control, and ns denotes no significant difference. 43 0 2 4 6 8 10 12 0 30 60 90 120 Time (days) SA (m gx 10 1 / tab let ) T2 T4 ns ns s s Figure 14: Comparison of treatments 2 (T2) and 4 (T4) for CSP technologies activ-vials for salicylic acid. S denotes a statistically significant (p < 0.05) difference from T2, the negative control, and ns denotes no significant difference. 44 0 2 4 6 8 10 12 0 30 60 90 120 Time (days) SA (m gx 10 1 / tab let ) T3 T4 ns s s s Figure 15: Comparison of treatments 3 (T3) and 4 (T4) for salicylic acid in a simulated use conditions. A relative 40-60% suppression of SA formation was observed for the CSP technologies Activ-Vial. 45 5 CONCLUSIONS A stability-indicating assay was established and validated suitable for analyses of aspirin and its degradation products in appropriate concentration ranges corresponding to levels expected from one (1) aspirin tablet containing 325 mg of aspirin. Formation of salicylic acid as the result of aspirin degradation was observed within the 120 days period studied under simulated use conditions of 30?C and 80% relative humidity with a total exposure rate of 3 minutes per day (three one minute periodic exposures). The extent of aspirin degradation was minimal in this time frame. Never-the-less, significant suppression of salicylic acid formation was demonstrated by the CSP Technologies Activ-Vial system when compared to ordinary PET prescription vials. Although minimal moisture ingress is a necessary characteristic of pharmaceutical product packaging and repackaging for use, additional properties are required to minimize relative humidity within vials when subjected to typical use conditions. The CSP technologies Activ-Vial is expected to therefore provided an advantage under typical consumer use conditions, particularly in humid geographical regions, for the protection of moisture sensitive pharmaceutical products. In retrospect, current regulatory guidelines offer little assurance of the integrity and stability of moisture sensitive drugs under typical use conditions due to trapped moisture once the vials are opened. 46 REFERENCES 1. ?The United States Pharmacopoeia,? 28th rev, 2699 (2005). 2. ?The United States Pharmacopoeia,? 28th rev, 2727, 2728 (2005). 3. ?The United States Pharmacopoeia,? 28th rev, 2396 (2005). 4. American society of Hospital Pharmacists. ASHP guidelines for single unit and unit dose packages of drugs. Am J Hosp Pharm. 34: 613-4. (1979). 5. Stolar MH. Expiration dates of repackaged drug products. Am J Hosp Pharm. 36:170 Editorial (1979). 6. http://athagan.members.atlantic.net/PFSFAQ/PFSFAQ-4-2.html date 8/01/2006 7. ?The United States Pharmacopoeia,? 28th rev, 2869 (2005). 8. http://www.csptechnologies.com date 08/20/2006. 9. Tacuchi V. Y, Cotton M. L, Yates C. H and Miller J. F., J.Pharm.Sci., 70:64- 7(1981). 10. R. G. Baum and F. F. Cantwell, Anal. Chem., 50, 280 (1978). 11. G. W. Peng, M. A. F. Gadalla, V. Smith, A. Peng and W. L. Chiou, J. Pharm. Sci, 67, 710 (1978). 12. R. G. Baum and F. F. Cantwell, ibid., 67, 1066 (1978). 13. J. F. Reepmeyer and R. D. Kirchhoefer, ibid., 68, 1167 (1979). 14. D. E. Guttman, ibid., 57, 1685 (1968). 15. J. Levine, ibid., 50, 506 (1961). 47 APPENDICES 48 Appendix I ? Representative Study sample chromatograms Figure 16: Chromatogram of Owen- Illinois closed, at day 30, salicylic acid (SA), RT 5.7 min and acetylsalicylsalicylic acid (ASA), RT 10.9 min; aspirin standard BA, RT 4.6 min. 49 Figure 17: Chromatogram of Owen- Illinois closed, at day 30, salicylic acid (SA), RT 5.7 min and acetylsalicylsalicylic acid (ASA), RT 10.9 min; aspirin standard BA, RT 4.6 min. 50 Figure 18: Chromatogram of CSP Technologies vial closed, at day 30, salicylic acid (SA), RT 5.6 min and acetylsalicylsalicylic acid (ASA), RT 10.8 min; aspirin standard BA, RT 4.6 min. 51 Figure 19: Chromatogram of CSP Technologies vial closed, at day 30, salicylic acid (SA), RT 5.6 min and acetylsalicylsalicylic acid (ASA), RT 10.8 min; aspirin standard BA, RT 4.6 min. 52 Figure 20: Chromatogram of Owen- Illinois vial periodically opened, at day 30, salicylic acid (SA), RT 5.4 min and acetylsalicylsalicylic acid (ASA), RT 10.3 min; aspirin standard BA, RT 4.6 min. 53 Figure 21: Chromatogram of Owen- Illinois vial periodically opened, at day 30, salicylic acid (SA), RT 5.4 min and acetylsalicylsalicylic acid (ASA), RT 10.3 min; aspirin standard BA, RT 4.6 min. 54 Figure 22: Chromatogram of CSP Technologies vial periodically opened, at day 30, salicylic acid (SA), RT 5.4 min and acetylsalicylsalicylic acid (ASA), RT 10.2 min; aspirin standard BA, RT 4.6 min. 55 Figure 23: Chromatogram of CSP Technologies vial periodically opened, at day 30, salicylic acid (SA), RT 5.4 min and acetylsalicylsalicylic acid (ASA), RT 10.3 min; aspirin standard BA, RT 4.6 min. 56 Figure 24: Chromatogram of Owen- Illinois vial continuously opened, at day 30, salicylic acid (SA), RT 5.4 min and acetylsalicylsalicylic acid (ASA), RT 10.2 min; aspirin standard BA, RT 4.6 min. 57 Figure25: Chromatogram of Owen- Illinois vial continuously opened, at day 30, salicylic acid (SA), RT 5.4 min and acetylsalicylsalicylic acid (ASA), RT 10.2 min; aspirin standard BA, RT 4.6 min. 58 Appendix II ? Tabulated Results Table 4 Owens-Illinois PET prescription vial Treatment 1 Closed Vial Environmental conditions: 30?C and 80% RH *325 mg aspirin = 249.2 mg salicylic acid ** outlier, omitted from statistics *** 40?C and 75% RH Sample ASA conc SA Conc ASA per tablet SA per tablet ASA SA equivalent* (?g/mL) (?g/mL) (mg) (mg) (% label) (% label) Time: 0 days Tablet 1 156.0 0.085 312.0 0.17 96.0 0.068 Tablet 2 170.8 0.154 341.7 0.31 105.1 0.124 Tablet 3 151.0 0.123 302.1 0.25 92.9 0.098 Tablet 4 157.5 0.522 315.0 1.05** 96.9 0.421** Tablet 5 153.2 0.134 306.3 0.27 94.3 0.107 Tablet 6 153.6 0.124 307.3 0.25 94.5 0.099 AVG 314.1 0.25 96.6 0.099 SD 14.27 0.050 4.39 0.0202 Time: 30 days Tablet 1 155.0 0.139 310.1 0.28 95.4 0.112 Tablet 2 166.2 0.145 332.5 0.29 102.3 0.116 Tablet 3 165.5 0.145 331.1 0.29 101.9 0.117 Tablet 4 164.9 0.286 329.7 0.57 101.4 0.230 Tablet 5 158.5 0.115 317.0 0.23 97.5 0.092 Tablet 6 152.6 0.312 305.2 0.62 93.9 0.251 AVG 320.9 0.38 98.7 0.153 SD 11.77 0.171 3.62 0.0686 Time: 60 days Tablet 1 150.7 0.080 301.5 0.16 92.8 0.064 Tablet 2 150.2 0.074 300.5 0.15 92.5 0.060 Tablet 3 152.8 0.128 305.6 0.26 94.0 0.102 Tablet 4 141.8 0.130 283.5 0.26 87.2 0.104 Tablet 5 153.0 0.128 306.0 0.26 94.2 0.102 Tablet 6 155.3 0.303 310.6 0.61 95.6 0.243 AVG 301.3 0.28 92.7 0.113 SD 9.42 0.167 2.90 0.0669 Time: 90 days Tablet 1 153.2 0.164 306.5 0.33 94.3 0.132 Tablet 2 148.2 0.093 296.4 0.19 91.2 0.075 Tablet 3 164.6 0.179 329.2 0.36 101.3 0.144 Tablet 4 153.4 0.078 306.8 0.16 94.4 0.062 Tablet 5 148.0 0.153 295.9 0.31 91.1 0.122 Tablet 6 153.1 0.147 306.2 0.29 94.2 0.118 AVG 306.8 0.27 94.4 0.109 SD 12.09 0.082 3.72 0.0328 Time: 120 days Tablet 1 156.2 0.124 312.4 0.25 96.1 0.099 Tablet 2 158.5 0.231 317.1 0.46 97.6 0.185 Tablet 3 161.2 0.159 322.3 0.32 99.2 0.127 AVG 317.3 0.34 97.6 0.137 SD 4.94 0.110 1.52 0.0440 Time: 150 days*** Tablet 1 146.4 0.129 292.9 0.26 90.1 0.104 Tablet 2 150.2 0.218 300.5 0.44 92.5 0.175 Tablet 3 165.2 0.343 330.4 0.69 101.7 0.275 AVG 307.9 0.46 94.7 0.185 SD 19.87 0.215 6.11 0.0862 59 Table 5 CSP Technologies activ-vial Treatment 2 Closed vial Environmental Conditions: 30?C and 80% RH Sample ASA conc SA Conc ASA per tablet SA per tablet ASA SA equivalent* (?g/mL) (?g/mL) (mg) (mg) (% label) (% label) Time: 0 days Tablet 1 156.0 0.085 312.0 0.17 96.0 0.068 Tablet 2 170.8 0.154 341.7 0.31 105.1 0.124 Tablet 3 151.0 0.123 302.1 0.25 92.9 0.098 Tablet 4 157.5 0.522 315.0 1.05** 96.9 0.421** Tablet 5 153.2 0.134 306.3 0.27 94.3 0.107 Tablet 6 153.6 0.124 307.3 0.25 94.5 0.099 AVG 314.1 0.25 96.6 0.099 SD 14.27 0.050 4.39 0.0202 Time: 30 days Tablet 1 158.1 0.107 316.2 0.21 97.3 0.086 Tablet 2 169.0 0.143 338.0 0.29 104.0 0.115 Tablet 3 146.2 0.127 292.5 0.25 90.0 0.102 Tablet 4 159.8 0.152 319.7 0.30 98.4 0.122 Tablet 5 147.0 0.156 294.0 0.31 90.4 0.125 Tablet 6 154.7 0.195 309.5 0.39 95.2 0.156 AVG 311.6 0.29 95.9 0.118 SD 17.11 0.059 5.26 0.0237 Time: 60 days Tablet 1 164.4 0.060 328.7 0.12 101.1 0.048 Tablet 2 160.8 0.082 321.5 0.16 98.9 0.066 Tablet 3 158.2 0.07 316.3 0.14 97.3 0.056 Tablet 4 165.9 0.110 331.8 0.22 102.1 0.088 Tablet 5 147.4 0.091 294.7 0.18 90.7 0.073 Tablet 6 151.3 0.091 302.7 0.18 93.1 0.073 AVG 316.0 0.17 97.2 0.067 SD 14.64 0.035 4.50 0.0141 Time: 90 days Tablet 1 152.6 0.069 305.3 0.14 93.9 0.056 Tablet 2 152.6 0.046 305.2 0.09 93.9 0.037 Tablet 3 154.1 0.053 308.1 0.11 94.8 0.043 Tablet 4 154.3 0.128 308.5 0.26 94.9 0.103 Tablet 5 146.8 0.053 293.6 0.11 90.3 0.042 Tablet 6 141.3 0.049 282.7 0.10 87.0 0.040 AVG 300.6 0.13 92.5 0.053 SD 10.32 0.063 3.17 0.0251 Time: 120 days Tablet 1 162.1 0.130 324.2 0.26 99.8 0.104 Tablet 2 162.2 0.076 324.3 0.15 99.8 0.061 Tablet 3 148.6 0.108 297.2 0.22 91.4 0.086 AVG 315.2 0.21 97.0 0.084 SD 15.63 0.055 4.81 0.0220 Time: 150 days*** Tablet 1 157.0 0.017 313.9 0.03 96.6 0.013 Tablet 2 157.0 0.027 314.0 0.05 96.6 0.022 Tablet 3 171.8 0.032 343.6 0.06 105.7 0.026 AVG 323.8 0.05 99.6 0.020 SD 17.11 0.015 5.27 0.0062 *325 mg aspirin = 249.2 mg salicylic acid ** outlier, omitted from statistics *** 40?C and 75% RH 60 Table 6 Owens-Illinois PET prescription vial Treatment 3 periodically opened vial Environmental conditions: 30?C and 80% RH Sample ASA conc SA Conc ASA per tablet SA per tablet ASA SA equivalent* (?g/mL) (?g/mL) (mg) (mg) (% label) (% label) Time: 0 days Tablet 1 156.0 0.085 312.0 0.17 96.0 0.068 Tablet 2 170.8 0.154 341.7 0.31 105.1 0.124 Tablet 3 151.0 0.123 302.1 0.25 92.9 0.098 Tablet 4 157.5 0.522 315.0 1.05** 96.9 0.421** Tablet 5 153.2 0.134 306.3 0.27 94.3 0.107 Tablet 6 153.6 0.124 307.3 0.25 94.5 0.099 AVG 314.1 0.25 96.6 0.099 SD 14.27 0.050 4.39 0.0202 Time: 30 days Tablet 1 162.0 0.179 323.9 0.36 99.7 0.143 Tablet 2 155.2 0.098 310.4 0.2 95.5 0.079 Tablet 3 169.9 0.163 339.7 0.33 104.5 0.131 Tablet 4 152.7 0.136 305.5 0.27 94 0.109 Tablet 5 160.1 0.147 320.1 0.29 98.5 0.118 Tablet 6 161.9 0.126 323.8 0.25 99.6 0.101 AVG 320.6 0.28 98.6 0.114 SD 12.02 0.057 3.7 0.0227 Time: 60 days Tablet 1 156.7 0.189 313.4 0.38 96.4 0.152 Tablet 2 148.1 0.138 296.3 0.28 91.2 0.111 Tablet 3 162.5 0.186 324.9 0.37 100.0 0.15 Tablet 4 164.9 0.146 329.8 0.29 101.5 0.117 Tablet 5 152.5 0.217 305.1 0.43 93.9 0.174 Tablet 6 153.9 0.263 307.9 0.53 94.7 0.211 AVG 312.9 0.38 96.3 0.152 SD 12.6 0.093 3.88 0.0373 Time: 90 days Tablet 1 152.1 0.255 304.2 0.51 93.6 0.204 Tablet 2 148.9 0.194 297.9 0.39 91.7 0.156 Tablet 3 143.7 0.284 287.3 0.57 88.4 0.228 Tablet 4 148 0.295 295.9 0.59 91 0.236 Tablet 5 161.8 0.334 323.6 0.67 99.6 0.268 Tablet 6 161.4 0.379 322.7 0.76 99.3 0.304 AVG 305.3 0.58 93.9 0.233 SD 14.88 0.128 4.58 0.0513 Time: 120 days Tablet 1 161.7 0.359 323.3 0.72 99.5 0.288 Tablet 2 156.6 0.407 313.2 0.81 96.4 0.327 Tablet 3 161.3 0.362 322.6 0.72 99.3 0.29 Tablet 4 177.9 0.497 355.8 0.99 109.5 0.399 Tablet 5 156.8 0.45 313.6 0.9 96.5 0.361 Tablet 6 AVG 325.7 0.83 100.2 0.333 SD 17.47 0.119 5.38 0.0476 *325 mg aspirin = 249.2 mg salicylic acid ** outlier, omitted from statistics 61 Table 7 CSP Technologies activ-vial Treatment 4 periodically opened vial Environmental conditions: 30?C and 80% RH Sample ASA conc SA Conc ASA per tablet SA per tablet ASA SA equivalent* (?g/mL) (?g/mL) (mg) (mg) (% label) (% label) Time: 0 days Tablet 1 156.0 0.085 312.0 0.17 96.0 0.068 Tablet 2 170.8 0.154 341.7 0.31 105.1 0.124 Tablet 3 151.0 0.123 302.1 0.25 92.9 0.098 Tablet 4 157.5 0.522 315.0 1.05** 96.9 0.421** Tablet 5 153.2 0.134 306.3 0.27 94.3 0.107 Tablet 6 153.6 0.124 307.3 0.25 94.5 0.099 AVG 314.1 0.25 96.6 0.099 SD 14.27 0.050 4.39 0.0202 Time: 30 days Tablet 1 180.2 0.082 360.4 0.16 110.9 0.066 Tablet 2 174.3 0.149 348.5 0.3 107.2 0.12 Tablet 3 159 0.06 317.9 0.12 97.8 0.048 Tablet 4 162.7 0.234 325.4 0.47 100.1 0.188 Tablet 5 169.3 0.103 338.7 0.21 104.2 0.083 Tablet 6 152.7 0.051 305.4 0.1 94 0.041 AVG 332.7 0.23 102.4 0.091 SD 20.35 0.138 6.26 0.0553 Time: 60 days Tablet 1 152.8 0.085 305.6 0.17 94 0.068 Tablet 2 146.7 0.09 293.4 0.18 90.3 0.073 Tablet 3 145.6 0.081 291.2 0.16 89.6 0.065 Tablet 4 148.6 0.086 297.2 0.17 91.4 0.069 Tablet 5 144.1 0.045 288.3 0.09 88.7 0.036 Tablet 6 152.6 0.087 305.3 0.17 93.9 0.07 AVG 296.8 0.16 91.3 0.063 SD 7.29 0.034 2.24 0.0136 Time: 90 days Tablet 1 157.8 0.127 315.7 0.25 97.1 0.102 Tablet 2 156.3 0.074 312.7 0.15 96.2 0.06 Tablet 3 155.3 0.072 310.6 0.14 95.6 0.058 Tablet 4 157.5 0.134 315 0.27 96.9 0.107 Tablet 5 144.8 0.159 289.7 0.32 89.1 0.128 Tablet 6 166.5 0.119 333 0.24 102.5 0.095 AVG 312.8 0.23 96.2 0.092 SD 13.88 0.069 4.27 0.0277 Time: 120 days Tablet 1 158.4 0.248 316.9 0.5 97.5 0.199 Tablet 2 164.1 0.184 328.3 0.37 101 0.147 Tablet 3 173.7 0.307 347.4 0.61 106.9 0.246 Tablet 4 165 0.256 330.1 0.51 101.6 0.206 Tablet 5 156.5 0.233 313 0.47 96.3 0.187 Tablet 6 AVG 327.1 0.49 100.6 0.197 SD 13.46 0.089 4.14 0.0356 *325 mg aspirin = 249.2 mg salicylic acid ** outlier, omitted from statistics 62 Table 8 Owens-Illinois PET prescription vial Treatment 5 Continuously open vial Environmental conditions: 30?C and 80% RH Sample ASA conc SA Conc ASA per tablet SA per tablet ASA SA equivalent* (?g/mL) (?g/mL) (mg) (mg) (% label) (% label) Time: 0 days Tablet 1 156.0 0.085 312.0 0.17 96.0 0.068 Tablet 2 170.8 0.154 341.7 0.31 105.1 0.124 Tablet 3 151.0 0.123 302.1 0.25 92.9 0.098 Tablet 4 157.5 0.522 315.0 1.05** 96.9 0.421** Tablet 5 153.2 0.134 306.3 0.27 94.3 0.107 Tablet 6 153.6 0.124 307.3 0.25 94.5 0.099 AVG 314.1 0.25 96.6 0.099 SD 14.27 0.050 4.39 0.0202 Time: 30 days Tablet 1 158.7 0.091 317.4 0.18 97.7 0.073 Tablet 2 153.8 0.128 307.6 0.26 94.6 0.103 Tablet 3 157.7 0.164 315.3 0.33 97.0 0.131 Tablet 4 157.4 0.159 314.7 0.32 96.8 0.127 Tablet 5 155.9 0.143 311.7 0.29 95.9 0.115 Tablet 6 153 0.187 306.0 0.37 94.1 0.150 AVG 312.1 0.29 96.0 0.117 SD 4.55 0.066 1.4 0.0267 Time: 60 days Tablet 1 161.4 0.317 322.9 0.63 99.3 0.254 Tablet 2 150.5 0.187 301.0 0.37 92.6 0.150 Tablet 3 156.9 0.287 313.8 0.57 96.6 0.231 Tablet 4 152.6 0.193 305.2 0.39 93.9 0.155 Tablet 5 150.9 0.343 301.7 0.69 92.8 0.275 Tablet 6 148.6 0.276 297.1 0.55 91.4 0.221 AVG 307.0 0.53 94.4 0.214 SD 9.64 0.129 2.97 0.0516 Time: 90 days Tablet 1 153.8 0.272 307.6 0.54 94.6 0.218 Tablet 2 155.4 0.325 310.9 0.65 95.7 0.261 Tablet 3 159.0 0.251 318.0 0.50 97.9 0.201 Tablet 4 153.4 0.318 306.7 0.64 94.4 0.255 Tablet 5 154.5 0.381 309.0 0.76 95.1 0.306 Tablet 6 157.4 0.314 314.8 0.63 96.9 0.252 AVG 311.2 0.62 95.7 0.249 SD 4.42 0.091 1.36 0.0364 Time: 120 days Tablet 1 170.2 0.346 340.4 0.69 104.7 0.278 Tablet 2 157.4 0.170 314.8 0.34 96.9 0.136 Tablet 3 AVG 327.6 0.52 100.8 0.207 Time: 150 days*** Tablet 1 173.3 0.493 346.5 0.99 106.6 0.396 Tablet 2 158.5 0.328 316.9 0.66 97.5 0.263 Tablet 3 AVG 331.7 0.82 102.1 0.329 *325 mg aspirin = 249.2 mg salicylic acid ** outlier, omitted from statistics *** 40?C and 75% RH