Accelerated aging: Prediction of chemical stability of pharmaceuticals

Cortisol in fish scales remains stable during extended periods of storage

Measurement of cortisol in fish scales is attracting considerable attention as a non-invasive indicator of chronic stress in wild populations. For many fish species of management and conservation interest, extensive scale collections exist that could provide extended records of individual stress responses, by combining cortisol measurements with life history information. However, it is not yet known how well cortisol is preserved in the scale during storage. To investigate the stability of scale cortisol, we accelerated potential degradation by storing scales from an individual farmed Atlantic salmon (Salmo salar) in an oven at 50°C for between 2 and 12 weeks. We found no significant relationship between scale cortisol concentration and either storage time or storage temperature. Cortisol concentrations in scales from the same fish were consistent (18.54-21.82 ng. g-1; coefficient of variation (CV) = 3.6%), indicating that scale cortisol can be reliably quantified, even in scales stored for varying periods of time or under different conditions. We also examined the effects of storage in real time using Atlantic salmon scales that were stored in paper envelopes at room temperature for between 3 and 32 years and found no significant relationship between scale cortisol concentration and storage time. Scale cortisol concentrations ranged from 4.05 to 135.37 ng.g-1 and levels of between-individual variability were high (CV = 61%). Given that scale cortisol does not degrade during long-term storage, historical scale collections and associated data describing fish life histories could potentially be used to develop bioindicators of physiological responses in fish populations. Further research is needed to understand scale cortisol variability and its biological relevance.

Mannitol-Coated Hydroxypropyl Methylcellulose as a Directly Compressible Controlled Release Excipient for Moisture-Sensitive Drugs: A Stability Perspective

BACKGROUND/OBJECTIVES

Hydroxypropyl methylcellulose (HPMC) is one of the most commonly used hydrophilic polymers in formulations of matrix tablets for controlled release applications. However, HPMC attracts moisture and poses issues with drug stability in formulations containing moisture-sensitive drugs.

METHODS

Herein, the moisture sorption behavior of excipients and drug stability using aspirin as the model drug in matrix tablets were evaluated, using HPMC and the newly developed mannitol-coated HPMC, under accelerated stability conditions (40 °C, 75% relative humidity) with open and closed dishes.

RESULTS

Tablets prepared with mannitol-coated HPMC showed a slower drug degradation rate compared to tablets prepared with directly compressible HPMC. Initial moisture content and hygroscopicity were stronger predictors of drug stability compared to water activity when comparing samples without similar moisture content. In the early stage (day 0 to 30), the aspirin degradation rate was similar in both open and closed conditions, as moisture content is the main degradation contributor. In the later stage (day 30 to 90), aspirin degradation was faster under closed conditions than under open conditions, likely due to autocatalytic effects caused by the volatile acidic by-product entrapped in the closed environment.

CONCLUSIONS

The findings from this study reinforced the importance of judicious excipient selection based on the understanding of excipient-moisture interactions to maximize the chemical stability of moisture-sensitive drugs. Mannitol-coated HPMC is a promising addition to the formulator's toolbox for the formulation of controlled release dosage forms by direct compression.

Early clinical drug product shelf-life setting using accelerated predictive stability and metabolite data for impurity qualification: A case study

This case study demonstrates how knowledge of degradation products together with predictions can establish a lean stability strategy using the accelerated predictive stability (APS) principles. Applying all available data for AZD4831, (R)-1-(2-(1-aminoethyl)-4-chlorobenzyl)-2-thioxo-2,3-dihydro-1H-pyrrolo[3,2-d]pyrimidin-4(5H)-one, a reliable predictive model was developed despite minor differences in technical batch tablet compositions. Early forced degradation studies were performed to map potential degradation pathways. The insights from these studies guided the design of an APS study, which in turn inform on a suitable clinical stability program, initial specification and shelf-life. The use of APS predictions of degradants as well as total impurities highlighted at an early stage, when designing the clinical stability program, the opportunity to identify which degradation product that would be shelf-life limiting. Hence, it was possible to guide the development stability activities and set an initial shelf-life of a tablet formulation. The presented study displays the importance of combining several sources of information in drug development, e.g., potential degradation pathways, accelerated stability, stability program design, metabolite data, and specification limits.

Prediction of Degradation Profiles for Various Sartans under Solvent-Free Mechanochemical Conditions

For the approval of a drug, the stability data must be submitted to regulatory authorities. Such analyses are often time-consuming and cost-intensive. Forced degradation studies are mainly carried out under harsh conditions in the dissolved state, often leading to extraneous degradation profiles for a solid drug. Oxidative mechanochemical degradation offers the possibility of generating realistic degradation profiles. In this study, a sustainable mechanochemical procedure is presented for the degradation of five active pharmaceutical ingredients (APIs) from the sartan family: losartan potassium, irbesartan, valsartan, olmesartan medoxomil, and telmisartan. High-resolution mass spectrometry enabled the detection of impurities already present in untreated APIs and allowed the elucidation of degradation products. Significant degradation profiles could already be obtained after 15-60 min of ball milling time. Many of the identified degradation products are described in the literature and pharmacopoeias, emphasizing the significance of our results and the applicability of this approach to predict degradation profiles for drugs in the solid state.

Advanced Chemical and Imaging Methods for Studying Structure Morphology and Excipients Solid State Transformations in Pharmaceutical Multiparticulate Formulations

The formulation of paediatric medicines faces significant challenges to meet the requirements for safe and accurate administration, while maintaining a suitable taste. Multiparticulate formulations have a strong potential to address these challenges because they combine dose flexibility with ease of administration. Understanding the stability of multiparticulate formulations over storage as a function of time and environmental parameters, such as humidity and temperature, is important to manage their commercialisation and use. In this work, we have expanded the toolkit of available techniques for studying multiparticulates beyond those such as scanning electron microscopy (SEM) and confocal laser scanning microscopy. We include advanced methods of environmentally-controlled SEM to monitor temperature- and humidity-induced changes in-situ, and a variety of Raman spectroscopies including stimulated Raman scattering microscopy to identify and localise the different ingredients at the surface and inside the multiparticulates. These techniques allowed unprecedented monitoring of specific changes to the particulate structure and distribution of individual ingredients due to product aging. These methods should be considered as valuable novel tools for in-depth characterisation of multiparticulate formulations to further understand chemical changes occurring during their development, manufacturing and long-term storage. We envisage these techniques to be useful in furthering the development of future medicine formulations.

Accelerated Predictive Stability Study of a Pediatric Drug Product for a Supplemental New Drug Application

In this paper, we report two Accelerated Stability Assessment Program (ASAP) studies for a pediatric drug product. Whereas the first study using a generic design failed to establish a predictive model, the second one was successful after troubleshooting the first study and customizing the study conditions. This work highlighted important lessons learned from designing an ASAP study for formulations containing excipients that could undergo phase change at high humidity levels. The stability predictions by the second ASAP model were consistent with available long-term stability data of the drug product under various storage conditions in two different packaging configurations. The ASAP model was part of the justifications accepted by the health authority to submit a stability package with reduced long-term stability data from the primary stability batches for a Supplemental New Drug Application (sNDA).

Science- and Risk-Based Stability Strategies to Support Product Lifecycle Changes

ICH Q12 asserts that science- and risk-based approaches are applicable to stability studies supporting Chemistry, Manufacturing and Controls (CMC) post-approval changes (PAC) to enable more timely implementation; however, no guidance or specific examples are provided to demonstrate how prior knowledge of the product can inform the risk assessment for the proposed change(s). Ten diverse case studies are presented in this manuscript to demonstrate how science- and risk-based stability strategies were used to support drug substance and product CMC PAC and lifecycle management activities. The accumulated stability knowledge held by original manufacturers of marketed products is substantial, and different elements of this knowledge base were used to assess the risks and impact of the proposed changes for confident change management. This paper provides ways to leverage science- and risk-based stability strategies as part of the post-approval change-management risk-mitigation strategy, which may enable a reduced stability data commitment and/or a reduced reporting category for change implementation.

Development and validation of method for the simultaneous determination of sulfamethazine, trimethoprim and doxycycline in veterinary formulation using high performance liquid chromatography

Sulfamethazine (SMZ), trimethoprim (TMP) and doxycycline (DOXY) are drugs of choice used in the treatment of intestinal and respiratory infections that affect poultry and swine. The aim of this study was develop and validate a simple, sensitive and fast method for the simultaneous determination of SMZ, TMP and DOXY in veterinary formulations by high-performance liquid chromatography. The separation was performed on a Macherey-Nagel C8 analytical column (4 × 125 mm, 5 μm), with a flow rate of 0.5 ml min-1 and detection at 268, 270 and 350 nm, for SMZ, TMP and DOXY, respectively. All measurements were performed in acetonitrile-water (45:55 v/v; pH 3.0). The analytical curves were linear (r > 0.9997) in the concentration range of 5.0-35.0 μg ml-1 for SMZ, 1.0-7.0 μg ml-1 for TMP and 7.0-13.0 μg ml-1 for DOXY. The method proved to be precise, robust, accurate and selective. In accelerated stability, the sample was analyzed for 6 months, with no major variations observed in organoleptic analysis and pH. Therefore, the developed method was proved to be suitable for routine quality control analyses for the simultaneous determination of SMZ, TMP and DOXY in pharmaceutical formulations.

Application of Accelerated Predictive Stability Studies in Extemporaneously Compounded Formulations of Chlorhexidine to Assess the Shelf Life

Industrially fabricated medicines have a well-defined shelf life supported by rigorous studies before their approval for commercialization. However, the shelf life of extemporaneous compounding topical formulations prepared at hospitals tends to be shorter, especially when no data are available to prove a longer stability period. Also, the storage conditions are unknown in many circumstances. Accelerated Predictive Stability (APS) studies have been shown to be a useful tool to predict in a faster and more accurate manner the chemical stability of extemporaneously compounded formulations requiring a minimum amount of formulation, thereby reducing the chemical drug waste per study. Shelf life will be allocated based on scientific data without compromising drug efficacy or safety. In this work, the APS approach was applied to the commercially available Cristalmina® (CR) and an extemporaneously compounded formulation of chlorhexidine (DCHX). A different degradation kinetic was found between DCHX and CR (Avrami vs. zero-order kinetics, respectively). This can explain the different shelf life described by the International Council for Harmonisation of Technical Requirements Registration Pharmaceuticals Human Use (ICH) conditions between both formulations. A predicted stability for the DCHX solution was obtained from the extrapolation of the degradation rate in long-term conditions from the Arrhenius equation. The estimated degradation from the Arrhenius equation for DCHX at 5 °C, 25 °C, and 30 °C at 365 days was 3.1%, 17.4%, and 25.9%, respectively. The predicted shelf life, in which the DCHX content was above 90%, was 26.67 months under refrigerated conditions and 5.75 and 2.24 months at 25 and 30 °C, respectively. Currently, the Spanish National Formulary recommends a shelf life of no longer than 3 months at room temperature for DCHX solution. Based on the predicted APS and confirmed by experimental long-term studies, we have demonstrated that the shelf life of DCHX extemporaneously compounded formulations could be prolonged by up to 6 months.

A Bayesian Approach to Kinetic Modeling of Accelerated Stability Studies and Shelf Life Determination

Kinetic modeling of accelerated stability data serves an important purpose in the development of pharmaceutical products, providing support for shelf life claims and expediting the path to clinical implementation. In this context, a Bayesian kinetic modeling framework is considered, accommodating different types of nonlinear kinetics with temperature and humidity dependent rates of degradation and accounting for the humidity conditions within the packaging to predict the shelf life. In comparison to kinetic modeling based on nonlinear least-squares regression, the Bayesian approach allows for interpretable posterior inference, flexible error modeling and the opportunity to include prior information based on historical data or expert knowledge. While both frameworks perform comparably for high-quality data from well-designed studies, the Bayesian approach provides additional robustness when the data are sparse or of limited quality. This is illustrated by modeling accelerated stability data from two solid dosage forms and is further examined by means of artificial data subsets and simulated data.

Food Monitoring: Limitations of Accelerated Storage to Predict Molecular Changes in Hazelnuts (Corylus avellana L.) under Realistic Conditions Using UPLC-ESI-IM-QTOF-MS

Accelerated storage is routinely used with pharmaceuticals to predict stability and degradation patterns over time. The aim of this is to assess the shelf life and quality under harsher conditions, providing crucial insights into their long-term stability and potential storage issues. This study explores the potential of transferring this approach to food matrices for shelf-life estimation. Therefore, hazelnuts were stored under accelerated short-term and realistic long-term conditions. Subsequently, they were analyzed with high resolution mass spectrometry, focusing on the lipid profile. LC-MS analysis has shown that many unique processes take place under accelerated conditions that do not occur or occur much more slowly under realistic conditions. This mainly involved the degradation of membrane lipids such as phospholipids, ceramides, and digalactosyldiacylglycerides, while oxidation processes occurred at different rates in both conditions. It can be concluded that a food matrix is far too complex and heterogeneous compared to pharmaceuticals, so that many more processes take place during accelerated storage, which is why the results cannot be used to predict molecular changes in hazelnuts stored under realistic conditions.

Predictive stability, novel HPLC-MS analysis and semi-automatic compounding process for the emergency implementation of a production line of pancuronium in injectable solution

During the early months of the COVID-19 pandemic, the international medical product supply chain was tight, causing breaks in the availability of neuromuscular blocking agents essential for the treatment of patients in intensive care units. The present study describes the pharmaceutical development of an injectable 2 mg/mL solution of pancuronium bromide (PC) in a very short lapse of time. The sterile solution was compounded into a good manufacturing practice grade A clean room, filtered (0.2 µm) and filled into 10 mL type I glass, manually sealed with bromobutyl rubber stoppers. A novel HPLC-MS stability indicating method for pancuronium quantification and its degradation product was developed and validated. This fast, sensitive and straightforward method was used to study the stability of the formulation using a semi-predictive method, enabling a very fast attribution of a temporary shelf-life, which was confirmed by a classic prospective stability study. The production line and the analytical tools set-up were performed in six weeks and the semi-predictive stability study was conducted in 90 days, allowing us to predict a shelf life, which was successfully confirmed by prospective study. In conclusion, using innovative methods, we were able to rapidly overcome the shortage of a critical drug.

The effect of long-term spaceflight on drug potency and the risk of medication failure

Pharmaceuticals selected for exploration space missions must remain stable and effective throughout mission timeframes. Although there have been six spaceflight drug stability studies, there has not been a comprehensive analytical analysis of these data. We sought to use these studies to quantify the rate of spaceflight drug degradation and the time-dependent probability of drug failure resulting from the loss of active pharmaceutical ingredient (API). Additionally, existing spaceflight drug stability studies were reviewed to identify research gaps to be addressed prior to exploration missions. Data were extracted from the six spaceflight studies to quantify API loss for 36 drug products with long-duration exposure to spaceflight. Medications stored for up to 2.4 years in low Earth orbit (LEO) exhibit a small increase in the rate of API loss with a corresponding increase in risk of product failure. Overall, the potency for all spaceflight-exposed medications remains within 10% of terrestrial lot-matched control with a ~1.5 increase in degradation rate. All existing studies of spaceflight drug stability have focused primarily on repackaged solid oral medications, which is important because non-protective repackaging is a well-established factor contributing to loss of drug potency. The factor most detrimental to drug stability appears to be nonprotective drug repackaging, based on premature failure of drug products in the terrestrial control group. The result of this study supports a critical need to evaluate the effects of current repackaging processes on drug shelf life, and to develop and validate suitable protective repackaging strategies that help assure the stability of medications throughout the full duration of exploration space missions.

Algorithm for the early prediction of drug stability using bayesian inference and multiple measurements: Application for predicting the stability of silodosin tablets

The stability of active pharmaceutical ingredients (APIs) and formulations has become a major chemistry, manufacturing, and control (CMC) concern in the pharmaceutical industry because it can determine the feasibility of research and development, the development period, and the development costs of a certain formulation. To streamline the research and development of pharmaceutical products and create useful pharmaceutical products at an early stage, a technology that predicts the stability of formulations at an early stage and with a high degree of accuracy is needed. When predicting the stability of a substance, highly reliable data are required; however, the stability data are affected by analytical variations that depend on the experimenter, measurement device, and conditions used. Although these variations greatly affect the prediction accuracy, a stability prediction method that considers these variations has not yet been developed. Here, short-term stability data under accelerated conditions were obtained at three institutions using silodosin tablets as a model sample. By combining Bayesian inference with the temporal change in the amount of the main degradation products obtained and the conventional humidity-corrected Arrhenius equation, we developed a new algorithm that provides a narrow confidence interval, even when using data with variations. By using this algorithm and setting an appropriate number of conditions, we were able to obtain a valid confidence intervals in a short period of time. Here, by performing more measurements than those suggested by the minimum measurement frequency indicated in the guideline specified in the International Council for Harmonisation (ICH) of Technical Requirements for Pharmaceuticals for Human Use, we developed a method that can be used to reasonably predict the long-term stability of the drugs, even if the data measurement interval is short. Our results will help solve various problems in today's pharmaceutical product development scenario and contribute to worldwide health and welfare.

Polyhydroxybutyrate Production from Methane and Carbon Dioxide by a Syntrophic Consortium of Methanotrophs with Oxygenic Photogranules without an External Oxygen Supply

Here, a syntrophic process was developed to produce polyhydroxy-β-butyrate (PHB) from a gas stream containing CH₄ and CO₂ without an external oxygen supply using a combination of methanotrophs with the community of oxygenic photogranules (OPGs). The co-culture features of Methylomonas sp. DH-1 and Methylosinus trichosporium OB3b were evaluated under carbon-rich and carbon-lean conditions. The critical role of O₂ in the syntrophy was confirmed through the sequencing of 16S rRNA gene fragments. Based on their carbon consumption rates and the adaptation to a poor environment, M. trichosporium OB3b with OPGs was selected for methane conversion and PHB production. Nitrogen limitation stimulated PHB accumulation in the methanotroph but hindered the growth of the syntrophic consortium. At 2.9 mM of the nitrogen source, 1.13 g/L of biomass and 83.0 mg/L of PHB could be obtained from simulated biogas. These results demonstrate that syntrophy has the potential to convert greenhouse gases into valuable products efficiently.

Copper-Catalyzed Racemization-Recycle of a Quaternary Center and Optimization Using a Combined Kinetics-DoE/MLR Modeling Approach

The copper-catalyzed racemization of a complex, quaternary center of a key intermediate on route to lanabecestat has been identified. Optimization and mechanistic understanding were achieved through the use of an efficient, combined kinetic-multiple linear regression approach to experimental design and modeling. The use of a definitive screening design with mechanistically relevant factors and a mixture of fitted kinetic descriptors and empirical measurements facilitated the generation of a model that accurately predicted complex reaction time course behavior. The synergistic model was used to minimize the formation of dimer byproducts, determine optimal conditions for batch operation, and highlight superheated conditions that could be accessed in flow, leading to a further increase in yield which was predicted by the original model.

Solid State Kinetics of Nitrosation Using Native Sources of Nitrite

While many reactive species are known to cause N-nitrosation, trace nitrite (NO₂^-), which may be present in several excipients, is a source of nitrosating agents in pharmaceutical formulations. In this study we have found that the salt form of NO₂^- can influence the favored nitrosation conditions and final amount of nitrosamine being formed. Using native levels of NO₂^-, most likely present as ammonium nitrite (NH₄NO₂), in microcrystalline cellulose, we have determined the kinetics of nitrosamine formation in solid state with dimethylamine substrate present in metformin, used as model compound. It was found that the competing degradation of NH₄NO₂ into N₂ and H₂O limited the amount of nitrosamine formation to a great extent. Empirically modelling the kinetic data predicted reaching at maximum 1.6% conversion over a hypothetical 3-year shelf-life. These results also showed that using other sources of NO₂^- as spiking reagents, such as NaNO₂, may lead to unrealistic worst-case situations when the main form of NO₂^- in the drug product (DP) under evaluation may be NH₄NO₂. As well, measuring NO₂^- in freshly manufactured excipients containing NO₂^- potentially as NH₄NO₂ may lead to biased high NO₂^- content, which is not representative of the actual amounts present at the time of DP manufacture.

Accelerated Shelf Life Modeling of Appearance Change in Drug Products Using ASAPprime®

An accelerated stability model approach was demonstrated to accurately predict the long-term shelf life of example drug substances and drug products (indigo carmine tablets and L-ascorbic acid powder) where appearance changes were shelf life-limiting. The products were exposed outside of packaging to conditions from 50-90 °C and 0-80% relative humidity for up to one month to accelerate appearance changes. The appearance changes of stressed samples were quantitated using the CIELAB color scale (calculated ΔE*), where a visual assessment of appearance changes likely to be noticeable was used to assign a ΔE* specification limit. ASAPprime^® software was employed to create an isoconversion paradigm, modeled in packaging by the moisture-modified Arrhenius equation, that predicted the color changes of the products within the error bars of the model to nine months at 25 °C/60% RH, 30 °C/65% RH, and 40 °C/75% RH. Overall, these case studies indicate that the ASAPprime^® approach for accelerated stability studies are a fast, accurate approach to modeling appearance changes.

Food-inspired innovations to improve the stability of active pharmaceutical ingredients

Food-processing and pharmaceutical industries share a lot of stability issues against the same physical, chemical, and microbiological phenomena. They also share some solutions to improve the stability as the use of preservatives and packaging. Ecological concerns lead to the development of tremendous innovations in food. Some of these innovations could also be beneficial in the pharmaceutical domain. The objective of this review is to evaluate the potential application of these findings in the pharmaceutical field and the main limits in terms of toxicity, environmental, economic and regulatory issues. The principal factors influencing the shelf-life were highlighted through the description of the stability studies usually performed in the pharmaceutical industry (according to European guidelines). To counter those factors, different solutions are currently available as preservatives and specific packaging. They were described and debated with an overview of recent food innovations in each field. The limits of the current solutions in the pharmaceutical field and the innovation in the food field have inspired a critical pharmaceutical outlook. The active and intelligent packaging for active pharmaceutical ingredients of the future is imagined.

Aggregation Time Machine: A Platform for the Prediction and Optimization of Long-Term Antibody Stability Using Short-Term Kinetic Analysis

Monoclonal antibodies are the fastest growing class of therapeutics. However, aggregation limits their shelf life and can lead to adverse immune responses. Assessment and optimization of the long-term antibody stability are therefore key challenges in the biologic drug development. Here, we present a platform based on the analysis of temperature-dependent aggregation data that can dramatically shorten the assessment of the long-term aggregation stability and thus accelerate the optimization of antibody formulations. For a set of antibodies used in the therapeutic areas from oncology to rheumatology and osteoporosis, we obtain an accurate prediction of aggregate fractions for up to three years using the data obtained on a much shorter time scale. Significantly, the strategy combining kinetic and thermodynamic analysis not only contributes to a better understanding of the molecular mechanisms of antibody aggregation but has already proven to be very effective in the development and production of biological therapeutics.

Physicochemical Stability of a Novel Tacrolimus Ophthalmic Formulation for the Treatment of Ophthalmic Inflammatory Diseases

Tacrolimus is an immunosuppressant used to treat a large variety of inflammatory or immunity-mediated ophthalmic diseases. However, there are currently no commercial industrial forms available that can provide relief to patients. Various ophthalmic formulations have been reported in the literature, but their stability has only been tested over short periods. The objective of this study was to evaluate the physicochemical stability of a preservative-free tacrolimus formulation (0.2 and 1 mg/mL) at three storage temperatures (5 °C, 25 °C and 35 °C) for up to nine months in a multidose eyedropper. Analyses performed were the following: visual inspection and chromaticity, turbidity, viscosity, size of micelles, osmolality and pH measurements, tacrolimus quantification by a stability-indicating liquid chromatography method, breakdown product research, and sterility assay. In an in-use study, tacrolimus quantification was also performed on the drops emitted from the eyedroppers. All tested parameters remained stable during the nine month period when the eyedrops were stored at 5 °C. However, during storage at 25 °C and 35 °C, several signs of chemical instability were detected. Furthermore, a leachable compound originating from a silicone part of the eyedropper was detected during the in-use assay. Overall, the 0.2 mg/mL and 1 mg/mL tacrolimus ophthalmic solutions were physicochemically stable for up to nine months when stored at 5 °C.

Modeling the long-term 2-8 °C stability profiles of a live, rotavirus vaccine candidate (RV3-BB) in various liquid formulations via extrapolations of real-time and accelerated stability data

To accelerate the formulation development of live-virus vaccine (LVV) candidates, more rapid approaches to rank-order formulations and estimate their real-time storage stability losses are needed. In this case-study, we utilize new and previously described stability data of a live, rotavirus vaccine candidate (RV3-BB) in three different liquid formulations to model and compare predicted vs. experimental RV3-BB stability profiles. Linear-regression extrapolations of limited real-time (2-8 °C) stability data and Arrhenius modeling of accelerated (15, 25, 37 °C) stability data provided predictions of RV3-BB real-time stability profiles (2-8 °C, 24 months). Good correlations of modeled versus experimental stability data to rank-order the RV3-BB formulations were achieved by employing (1) a high-throughput RT-qPCR assay to measure viral titers, (2) additional assay replicates and stability time-points, and (3) a -80 °C control for each formulation to benchmark results at each stability time-point and temperature. Instead of accumulating two-year, 2-8 °C storage stability data, the same rank-ordering of the three RV3-BB formulations could have been achieved by modeling 37°, 25°, 15° (and 2-8 °C) stability data over 1, 3 and 12 months, respectively. The results of this case-study are discussed in the context of accelerating LVV formulation development by expeditiously identifying stable formulations, estimating their shelf-lives, and determining vaccine vial monitoring (VVM) designations.

Design of experiments and multivariate analysis approach to study dissolution stability of a modified-release drug product to support lean design strategies

OBJECTIVE

The purpose of this paper is to present the use of Design of Experiments and multivariate analysis for evaluation of a modified-release drug product stability to support post-approval lean stability approaches. The focus of the paper was to investigate potential root-causes for acceleration of dissolution upon stability.

METHODS

For statistical evaluation of stability data, multiple linear regression statistics was used. The design space of the stability study was modeled using MODDE 12.1 software. For experimental set-up, parameters such as Temperature, Time, Packaging, Batch, and Active Pharmaceutical Ingredient supplier were selected.

RESULTS

With multiple linear regression modeling of the all generated stability data until six months, we were able to identify or confirm the Stability-related quality attributes and Shelf life limiting attributes. From the multiple linear regression correlation coefficients, we have evaluated that decrease of an antioxidant upon stability could cause potential shift in dissolution. However, main factors for accelerated dissolution can be attributed to other material and process variables. In the last part of the study, we have shown the usefulness of these methodologies for supporting lean stability approaches. With enhanced drug product knowledge, we designed two reduced long-term stability studies and showed that with 'One-half' reduced design, we would still be able to confirm 24-month shelf life.

CONCLUSIONS

Implementing Quality by design approaches on stability studies could reduce the need for excessive analytical testing, help to evaluate meaningfulness of the data and set a risk-based stability testing strategy.

Ball milling - a new concept for predicting degradation profiles in active pharmaceutical ingredients

A method for forced oxidative mechanochemical degradation of active pharmaceutical ingredients (APIs) using clopidogrel hydrogensulfate as a model compound is presented. Considerable and selective formation of degradants occurs already after very short reaction times of less than 15 minutes and the nature of the products is strongly dependent on the used oxidant.

Accelerated Stability Assessment Program to Predict Long-term Stability of Drugs: Application to Ascorbic Acid and to a Cyclic Hexapeptide

During pharmaceutical development, the stability of the product is assessed during long-term study. If any stability issues are discovered at this point of the process, it will result in re-formulation and important loss of time and cost. Therefore, important efforts are made in order to select the most stable product. Nevertheless, predicting the stability of the developed product at early stage of the development is challenging. Accelerated stability assessment program (ASAP), based on modified Arrhenius equation and isoconversion approach, appears as an interesting tool allowing to evaluate stability and shelf-life of pharmaceutical product in a short period of time. Nevertheless, few studies using these approaches are published in the literature, and the majority concern small drug molecules. Here, this approach was applied on a small drug molecule, ascorbic acid (AA), and on a cyclic hexapeptide named cFEE. AA and cFEE have been exposed to various temperatures for a maximum of 3 weeks, and then analyzed by capillary electrophoresis coupled to UV detection (CZE-UV) for AA or LC-MS for cFEE. The level of major degradation products was used to build ASAP models and predict the stability of both compounds. Comparison between predicted and long-term data were found accurate for both compounds undergoing two different degradation pathways (oxidation and hydrolysis), confirming the real interest of accelerated predicting stability approach for consistent determination of long-term stability shelf-life of pharmaceutical products.

Reduced deliquescency of isosorbide by cocrystallization and mechanisms for hygroscopicity

Isosorbide (ISO) is an effective hyperosmotic agent that can be administrated orally and is used as a therapeutic agent for brain pressure drop, glaucoma, and Meniere's disease. However, the critical relative humidity (CRH) of ISO is about 48% RH at 25 °C, and it deliquesces in humid environments. In this study, we attempted to reduce the deliquescence of ISO using cocrystallization and analyze the water adsorption mechanism from the crystal structure. Four new ISO cocrystals with piperazine (PZ), hydrochlorothiazide (HCT), 3,5-dihydroxybenzoic acid (35DHBA), or gallic acid (GA) were identified. The dynamic vapor sorption analyses demonstrated that all the cocrystals showed higher CRHs than the ISO crystal. Although water adsorption below the CRH was observed for all cocrystals, the water molecules adsorbed in the ISO-PZ and ISO-GA cocrystals were lower than those in the ISO crystal. Investigation of the crystal structures suggested that the amount of water adsorbed might be related to the degree of exposure of the ISO hydroxyl groups on the crystal surface. Given the CRH, water adsorption below the CRH, thermal stability, apparent dissolution rate, and toxicity level of the coformer, the ISO-GA cocrystal is the most suitable for preparing a solid formulation of ISO.

Development of an Accelerated Stability Model to Estimate Purple Corn Cob Extract Powder (Moradyn) Shelf-Life

Moradyn is an Italian purple corn variety whose cobs represent a rich source of polyphenols. At the industrial level, they are used to produce a dried extract (MCE) by the addition of 20% Arabic gum. In order to evaluate the extract solid-state stability, an innovative accelerated stress protocol was developed following the isoconversion approach. The degradation kinetics of cyanidin-3-O-glucoside (C3G), the most suitable marker to monitor the overall MCE degradation status, was monitored under five temperature–humidity (RH) combinations. These data were used to build a mathematical model, able to estimate the C3G stability at 25 °C and 30% RH, whose predictiveness was further assessed by comparing the predicted vs. experimental C3G isoconversion time. Finally, by applying this model, the expiry date of the extract was calculated to be within 26–33 days, confirming that the addition of 20% Arabic gum is insufficient to stabilize MCE and highlighting the need of a new formula in order to prolong MCE shelf-life.

Sounding out stability of enteric coated dosage forms using Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS)

Stability testing is essential in the pharmaceutical industry to determine product shelf- life and the conditions under which drug products should be stored. Stability testing involves a complex set of procedures, considerable cost, time, and scientific expertise to build quality, efficacy and safety in a drug formulation. This paper highlights a new complementary approach to stability testing called Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS). BARDS measurements are based on reproducible changes in the compressibility of a solvent during dissolution. It is monitored acoustically via associated changes in the frequency of induced acoustic resonances. This study presents a novel approach to track the change of various drug formulations to determine the formulation's stability. Pellets, tablet and multiple-unit pellet system (MUPS) formulations were investigated to examine the effect of polymer coating and formulation core degradation over time. In combination with minimal usage of Ultra Violet - Visible Spectroscopy, BARDS can effectively track these changes. The technique offers a rapid approach to characterizing pharmaceutical formulations. BARDS can enable rapid development of solid drug formulation dissolution and disintegration testing as an In-Process Control test and drug stability analysis. The data show that a solid oral dose formulation has an intrinsic acoustic signature specific to the method of manufacture, excipient composition and elapsed time since the production of a product. BARDS data are also indicative of which aspect of a formulation may be unstable, whether a coating, sub-coating or core. It is potentially a time-efficient, cost-effective and greener approach to testing coating stability, disintegration and overall formulation stability.

Identification of degradation impurity of TGR5 receptor agonist-ZY12201 by LC-MS technique during force degradation study

Forced degradation study is a systemic characterization of degradation products of active pharmaceutical ingredient (API) at conditions which posses more harsh environment that accelerates degradation of API. Forced degradation and stability studies would be useful in selection of proper, packaging material and storage conditions of the API. These are also useful to demonstrate degradation pathways and degradation products of the API and further characterisation of the degradation products using mass spectrometry. TGR5 is a G protein-coupled receptor, activation of which promotes secretion of glucagon-like peptide-1 (GLP-1) and modulates insulin secretion. The potent and orally bioavailable TGR5 agonist, ZY12201, shows activation of TGR5 which increase secretion of GLP-1 and help in lowering blood glucose level in animal models. Hence it is necessary to establish and study degradation pathway and stability of API for better handling and regulatory approval. Force degradation studies of ZY12201 have shown presence of one oxidative impurity during oxidative degradation in HPLC analysis. The oxidized product is further characterized by LC-MS to elucidate structure of impurity and characterize its degradation pathway.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s42452-021-04660-y.

The use of polymer blends to improve stability and performance of electrospun solid dispersions: The role of miscibility and phase separation

Solid dispersion-based nanofiber formulations of poorly soluble drugs prepared by electrospinning (ES) with a water-soluble polymer, can offer significant improvements in drug dissolution for oral drug administration. However, when hygroscopic polymers, such as polyvinylpyrrolidone (PVP) are used, environmental moisture sorption can lead to poor physical stability on storage. This study investigated the use of polymer blends to modify PVP-based ES formulations of a model poorly soluble drug, fenofibrate (FF), to improve its physical stability without compromising dissolution enhancement. FF-PVP ES dispersions demonstrated clear dissolution enhancement, but poor storage stability against high humidity. Polymer blends of PVP with Eudragit E, Soluplus and hypromellose acetate succinate (HPMCAS), were selected because of the low intrinsic moisture sorption of these polymers. The drug-polymer and polymer-polymer miscibility study revealed that FF was more miscible with Eudragit E and Soluplus than with PVP and HPMCAS, and that PVP was more miscible with HPMCAS than Eudragit E and Soluplus. This led to different configurations of phase separation in the placebo and drug-loaded fibres. The in vitro drug release data confirmed that the use of PVP-Eudragit E retained the dissolution enhancement of the PVP formulation, whereas PVP-Soluplus reduced the drug release rate in comparison to FF-PVP formulations. The moisture sorption results confirmed that moisture uptake by the polymer blends was reduced, but formulation deformation occurred to phase-separated blend formulations. The data revealed the importance of miscibility and phase separation in understanding the physical stability of the ES fibre mats. The findings provide insight into the design of formulations that can provide dissolution enhancement balanced with improved storage stability.

A novel biocompatible formate bridged 1D-Cu(ii) coordination polymer induces apoptosis selectively in human lung adenocarcinoma (A549) cells

Copper compounds are promising candidates for next-generation metal anticancer drugs. Therefore, we synthesized and characterized a formate bridged 1D coordination polymer [Cu(L)(HCOO)₂]_n, (L = 2-methoxy-6-methyl-3-((quinolin-8-ylimino)methyl)chroman-4-ol), PCU1, wherein the Cu(ii) center adopts a square pyramidal coordination environment with adjacent CuCu distances of 5.28 Å. Primarily, in vitro DNA interaction studies revealed a metallopolymer which possesses high DNA binding propensity and cleaves DNA via the oxidative pathway. We further analysed its potential on cancerous cells MCF-7, HeLa, A549, and two non-tumorigenic cells HEK293 and HBE. The selective cytotoxicity potential of PCU1 against A549 cells driven us to examine the mechanistic pathways comprehensively by carrying out various assays viz, cell cycle arrest, Annexin V-FTIC/PI assay, autophagy, intercellular localization, mitochondrial membrane potential 'MMP', antiproliferative assay, and gene expression of TGF-β and MMP-2.

Immobilized anticancer agents and metal nanoparticles in a matrix of gellan: achievements and prospects

A review is devoted to recent achievements in development of anticancer drugs based on natural polysaccharide – gellan that possesses coil-helix conformational transition, sol-gel phase transition, thermo- and salt sensitivity. The characteristics of high- and low-acyl gellan are briefly given and the influence of mono- and multivalent metal ions on the gelation efficiency is described. The mucoadhesive properties of gellan and its modified derivatives are briefly considered in the context of application in pharmacy as oral, buccal, nasal, ophthalmologic, vaginal forms. The main attention is paid to anticancer drugs, gold and silver nanoparticles immobilized within gellan matrix by chemical bonds, physical adsorption and chemosorption. The state-of-the art and perspectives of development of plasmonic photothermal therapy of cancer cells that is one of the promising direction of nanomedicine in diagnosis and treatment of oncological diseases are highlighted. It is outlined that the further strategy of development and application of plasmonic photothermal therapy into clinical practice is due to selection of metal nanoparticles with optimal sizes, high concentration, low cytotoxicity and suitable optical characteristics.

Unveiling the Amphotericin B Degradation Pathway and Its Kinetics in Lipid-Based Solutions

The purpose of this work was to determine the degradation pathway of Amphotericin B (AmB) and its kinetics in lipid-based solutions. Mixtures of AmB in lipophilic solvent media were stored under different conditions, such as surface area, temperature, light exposure, presence of antioxidants and other co-solutes. AmB was quantified by HPLC and UV-Vis spectrometry. Empirical models were proposed, and degradation rate constants were estimated by nonlinear regression. The HPLC method was precise and accurate with linearity from 4.45 to 52.0 nM. Surface area studies revealed that adsorption to glass did not affect AmB loss. Unsaturated oils and methanol better preserved AmB compared to medium chain-triglyceride. Temperature increased AmB loss in a nonlinear behavior and the presence of antioxidants reduced its degradation. Under dark conditions, autoxidation was the predominant degradation pathway of AmB in oil, which undergoes a complex degradation. Under light exposure, photo-oxidation accounted for AmB loss, which appeared to be of pseudo-first order. AmB oily samples should be preferably stored in glass vials protected from light with the addition of antioxidants. Furthermore, this work encourages further investigation in other media for future complex modeling and estimation of AmB degradation and kinetics in lipid-based formulations.

Innovations in Thermal Processing: Hot-Melt Extrusion and KinetiSol® Dispersing

Thermal processing has gained much interest in the pharmaceutical industry, particularly for the enhancement of solubility, bioavailability, and dissolution of active pharmaceutical ingredients (APIs) with poor aqueous solubility. Formulation scientists have developed various techniques which may include physical and chemical modifications to achieve solubility enhancement. One of the most commonly used methods for solubility enhancement is through the use of amorphous solid dispersions (ASDs). Examples of commercialized ASDs include Kaletra®, Kalydeco®, and Onmel®. Various technologies produce ASDs; some of the approaches, such as spray-drying, solvent evaporation, and lyophilization, involve the use of solvents, whereas thermal approaches often do not require solvents. Processes that do not require solvents are usually preferred, as some solvents may induce toxicity due to residual solvents and are often considered to be damaging to the environment. The purpose of this review is to provide an update on recent innovations reported for using hot-melt extrusion and KinetiSol® Dispersing technologies to formulate poorly water-soluble APIs in amorphous solid dispersions. We will address development challenges for poorly water-soluble APIs and how these two processes meet these challenges.

Impact of Magnesium Stearate Content: Modeling of Drug Degradation Using a Modified Arrhenius Equation

To accelerate drug development, the pharmaceutical industry is working to shorten and improve studies on stability. The Accelerated Stability Assessment Program (ASAP) incorporating the humidity-corrected Arrhenius equation as an accelerated methodology has been proposed for both drug substances and drug products. In this study, the effect of magnesium stearate (MgSt) content on the chemical stability of acetylsalicylic acid was evaluated as a model system of drug-excipient compatibility studies using ASAP. In the acetylsalicylic acid powder blends, temperature and humidity showed a first-order linear response to the natural logarithm of the reaction rate constant, and MgSt content also showed a first-order linear response. A polynomial model was built in which temperature, humidity, and MgSt content were independent each other. The fitting index of the model, the coefficient of determination, was 0.9567, which was a good fit. In the long-term stability study (25 °C/60% relative humidity, 6 months), there was good agreement in total between measured values and model-predicted values. Using this model, we inferred that the degradation rates were depended on MgSt content at the fixed temperature and humidity because the micro-environmental pH of the excipient was catalytically affected. Applying this model equation can significantly reduce the duration of formulation design and stability studies and save time and costs in drug development.

Measurement, analysis and prediction of amoxicillin oral dose stability from integrated molecular description approach and accelerated predictive stability (APS)

Background

Stability of low amoxicillin oral dosage form (5 mg) used in reintroduction drug test was not fully documented. Furthermore, the impact of (1) salt moiety of amoxicillin and (2) amoxicillin – excipient interactions upon the antibiotic formulation stability during the storage was not characterized so that the estimation of the pharmaceutical expiration date from shelf-life was uncertain. Thus, the main goal of this study was to estimate the shelf-life of two formulations of amoxicillin, using a semi-predictive methodology.

Methods

Amoxicillin sodium (AS) and amoxicillin trihydrate (ATH), corresponding to 5-mg amoxicillin, were compounded with microcrystalline cellulose (MCC) in oral hard capsules which were, then, submitted to four environmental conditions (25 °C / 60% or 80% relative humidity (RH); 40 °C / 75% RH; 60 °C / 5% RH) in climatic chambers for 45 and 84 days. Therefore, the characterization of amoxicillin-MCC mixture was assessed by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) The profiles of amoxicillin content (determined by stability indicating chromatographic method) as a function of storage time, temperature and RH were fitted to pre-defined kinetic models performed by accelerated predictive stability (APS).

Results

ATR-FTIR analysis of AS, ATH, MCC and bulk specimens stored in heated and humid atmosphere confirmed water sorption to cellulose described by a broad and unresolved 3600 to 3000 cm−1 band associated with (1) general intramolecular and intermolecular hydrogen bonding between water and hydroxyl groups of the cellulose, and with (2) free hydroxyl in cellulose. Moreover, a dramatic decrease of absorption at 1776 and 1687 cm−1 respectively characteristic of the β-lactam ring (νC=O) and amide group (νC=O), was revealed as a consequence of AS and ATH degradation caused by moisturization of bulk. Amoxicillin degradation was established by chromatographic analysis showing faster AS degradation than ATH throughout time exposure. The combined effects of temperature – RH were successfully modeled by APS, where AS and ATH showed accelerated (auto-catalysis degradation mechanism) and linear degradation, respectively. The faster AS degradation was assumed to be linked to lower hydrogen donor to hydrogen acceptor count ratio and polar surface than ATH, increasing the probability of AS hydrolysis by water adsorption to AS-MCC solid dispersion (e.g., by reduction of protective intramolecular hydrogen bonds between AS molecules). Furthermore, the compounding which involved a drastic homogenization of solids may have affected the crystalline degree of MCC with an increase of amorphous phase more sensitive to water adsorption.

Conclusions

The improvement of amoxicillin compounding for oral dose forms might be rationalized by taking into account the molecular descriptors of salt moiety and excipients, improved by the choice of an appropriate process of production, characterized from infrared vibrational spectroscopy and chromatographic analysis and finally predicted from accelerated stability assays.

Prediction of saxagliptin stability using a new approach based on Partial Least Squares and Design of Experiments

The objective of this study was to assess the possibility of applying Partial Least Squares (PLS) statistics with the use of experimental design approach towards stability evaluation of the Saxagliptin drug product. The influences of temperature, time, dose, packaging, batch, and oxygen protection were analyzed for identification of critical factors responsible for degradation of saxagliptin and prediction of impurity levels at various storage conditions. Predicted levels of the impurity DP-2 were lower for at least 0.2 % when the drug product was protected from oxygen after its manufacture. Additionally, the PLS model revealed that the lower strength is at least twice less stable concerning impurity DP-1. Based on this analysis shelf life for Zone II was proposed at 24 months with high reliability. Comparison of the PLS model estimates with the measured stability data at shelf life revealed good predictive ability of the developed model. Moreover, PLS predictions of DP-1 and Total impurities were more accurate than those obtained with a standard linear least squares regression, while DP-2 predictions were at least as accurate. We can thus propose a more extensive use of this approach for stability evaluation of pharmaceuticals.

Stability of Ophthalmic Atropine Solutions for Child Myopia Control

Myopia is an ophthalmic condition affecting more than 1/5th of the world population, especially children. Low-dose atropine eyedrops have been shown to limit myopia evolution during treatment. However, there are currently no commercial industrial forms available and there is little data published concerning the stability of medications prepared by compounding pharmacies. The objective of this study was to evaluate the stability of two 0.1 mg/mL atropine formulations (with and without antimicrobiobial preservatives) for 6 months in two different low-density polyethylene (LDPE) multidose eyedroppers. Analyses used were the following: visual inspection, turbidity, chromaticity measurements, osmolality and pH measurements, atropine quantification by a stability-indicating liquid chromatography method, breakdown product research, and sterility assay. In an in-use study, atropine quantification was also performed on the drops emitted from the multidose eyedroppers. All tested parameters remained stable during the 6 months period, with atropine concentrations above 94.7% of initial concentration. A breakdown product (tropic acid) did increase slowly over time but remained well below usually admitted concentrations. Atropine concentrations remained stable during the in-use study. Both formulations of 0.1 mg/mL of atropine (with and without antimicrobial preservative) were proved to be physicochemically stable for 6 months at 25 °C when stored in LDPE bottles, with an identical microbial shelf-life.

Rapid TLC with Densitometry for Evaluation of Naproxen Stability

The purpose of the work was to develop such chromatographic conditions that allowed to separate as many naproxen degradation products as possible. In order to follow this process, thin-layer chromatography (TLC) coupled with densitometry and spectrodensitometry was used. A forced degradation study was performed using an ethanolic solution of naproxen spotted on silica gel plates, existing in the form of an aqueous solution at various pH values, and as solution prepared in saline and in hydrogen peroxide. Degradative effect of UV light on naproxen was watched in the context of naproxen spotted on plates precoated with silica gel and exposed to UV light, and also for its solution treated with UV light. However, the solution of naproxen prepared in water at pH ≈ 2.60 undergoes the largest changes as the results of its exposure to UV light during 10 h. Stressed samples of naproxen were analyzed by using a new and well validated TLC procedure including toluene (TOL)—acetone (ACE)—chloroform (CHL) (2:5:12, v/v/v) as mobile phase A and glacial acetic acid (AcOH)—n-hexane (Hex)—acetone (ACE)-(0.10:10:10, v/v/v) as mobile phase B. As the newly developed TLC-densitometric method can effectively separate the substances about pharmaceutical significance from products of its degradation, which are formed as a result of stress studies, is considered to be a good alternative and important tool in routine quality control and stability testing of naproxen in pharmaceutical formulations. These results indicate that proposed TLC-densitometric method is cost-effective, rapid, specific, accurate, and precise. This TLC procedure is comparable to HPLC and UPLC method in terms of detection the number of degradation products of naproxen. In addition, it realizes the criterion of linearity. A major advantage and novelty of proposed method is its low cost and ability to analyze examined drug and all degradation products simultaneously, including those which can be observed under intensive UV radiation exposure of naproxen solution which are not described by previous HPTLC studies available in the literature.

Composing Novel Diclofenac Potassium and l-Proline Salt Cocrystal as a Strategy to Increase Solubility and Dissolution

This research dealt with the multicomponent crystal developed from diclofenac potassium and l-proline to improve the pharmaceutical performance of this anti-inflammatory drug. Slow evaporation of the component mixture at a 1:1 M ratio, supported by ultrasonication, yielded a new salt cocrystal, which was characterized using thermal analysis, Karl Fischer titration, infrared spectrophotometry, powder diffractometry, and single crystal diffractometry. This salt cocrystal was confirmed as a tetrahydrate that comprised diclofenac potassium, l-proline, and water (1:1:4), named DKPH. The new salt cocrystal enhanced the solubility of diclofenac potassium by up to 3.56 folds and accelerated the intrinsic dissolution rate of 3.36 folds. It was supported by the solid and solution phase intermolecular interaction study. A different phase, which indicated a monohydrate form of the salt cocrystal, was found from the low humidity chamber during the isotherm sorption study. However, the tetrahydrate, DKPH, was proven as a stable form under ambient conditions.

Utilization of risk-based predictive stability within regulatory submissions; industry’s experience

Risk-Based Predictive Stability (RBPS) tools, such as the Accelerated Stability Assessment Program (ASAP) and other models, are used routinely within pharmaceutical development to quickly assess stability characteristics, especially to understand mechanisms of degradation. These modeling tools provide stability insights within weeks that could take months or years to understand using long-term stability conditions only. Despite their usefulness, the knowledge gained through these tools are not as broadly used to support regulatory filing strategies. This paper aims to communicate how industry has used RBPS data to support regulatory submissions and discuss the regulatory feedback that was received.

Insights on the role of excipients and tablet matrix porosity on aspirin stability

Excipient-moisture interaction can be a critical attribute in determination of product stability. This study aimed to investigate influence of integrating excipients having different moisture interaction into moisture sensitive drug formulations. Aspirin was formulated with maize starch (MS), microcrystalline cellulose (MCC) and calcium hydrogen phosphate dihydrate (DCP). The excipients were evaluated for their inherent moisture content and water activity. Tablets fabricated at different compression pressures were exposed to 40 °C, 75% relative humidity for a stipulated period before analyzing for aspirin degradation. The results revealed that while MS had higher moisture content, the water activity was relatively low. Consequently, MS tablets had lower aspirin degradation than MCC and DCP tablets. In contrast, high water activity of DCP resulted in greater aspirin degradation. This was despite the low moisture content of DCP. Influence of tablet porosity on aspirin degradation was minimal. This illustrated the fugacity of moisture, possessing high thermodynamic activity and physical spatial delimitation would not suppress its distribution. The findings suggested that excipients possessing high water retentive capacity could potentially be useful as internal tablet desiccants by acting as a moisture scavenger. This study also highlights the importance of water activity in preformulation studies related to the choice of excipients.