Abstract
The aim of the study was to examine the influence of non-freezing water (NFW) contents bound to hydroxypropyl methylcellulose (HPMC) or hydroxypropyl cellulose (HPC) binary mixtures using acetylsalicylic acid (ASA) as a model moisture-sensitive ingredient. Polysaccharides with significantly different physicochemical properties were mixed with acetylsalicylic acid at a ratio 1:1 (w/w). The measurements of NFW contents of hydrated samples were carried out using differential scanning calorimetry (DSC). In the method used, the dry mass normalized dependency of melting enthalpy (ΔH) and respective contents of water was found to be linear. NFW values were calculated after extrapolation ΔH to 0. For stability studies, HPC/ASA and HPMC/ASA mixtures were stored at 40°C and 75% RH for 5 weeks in the climatic chamber. The ASA hydrolysis was investigated using UV-Vis spectrophotometry. The amounts of NFW calculated for raw HPMC 3 cP and 100,000 cP were 0.49 and 0.42 g g−1, while for polymer and ASA mixtures, prepared from HPC type LF (126 cP) and MF (6300 cP) as well as from HPMC 3 cP and 100,000 cP were 0.23, 0.28 g g−1, 0.21 g g−1, and 0.33 g g−1 respectively. The measured NFW values were connected with appropriate concentrations of unhydrolyzed ASA.
Highlights
Chemical stability is an important factor of the drug quality because it is directly related to purity, efficacy, and safety of pharmacotherapy
It is possible that for concentrations of water under non-freezing water (NFW) content (0.49 g g−1 in this case—Table III), most bound molecules are being strongly restrained by the hydroxyl groups of hydroxypropyl methylcellulose (HPMC) chains
We examined the influence of viscosity and contents of non-freezing water on the stability of acetylsalicylic acid as a model moisture sensitive ingredient
Summary
Chemical stability is an important factor of the drug quality because it is directly related to purity, efficacy, and safety of pharmacotherapy. The stability of a medicinal product as a whole depends on the properties of the active pharmaceutical ingredient (API), and on the formulation and/or method of manufacture. One of the most important concepts in drug design is understanding the intrinsic stability of the API molecule and its degradation pathways. The most frequently encountered mechanism of drug degradation is hydrolysis, oxidation, and to some extent, photolysis (1). In multi-component heterogeneous systems, the degradation of the API can be more complex and may be the result of more than one factor – for example, hydrolysis with further oxidation, or vice versa [1]. Drug stability is a constant interest of many research teams [2,3,4,5,6]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
