Abstract
PurposeTo resolve contradictions found in morphology of hydrating hydroxypropylmethyl cellulose (HPMC) matrix as studied using Magnetic Resonance Imaging (MRI) techniques. Until now, two approaches were used in the literature: either two or three regions that differ in physicochemical properties were identified.MethodsMultiparametric, spatially and temporally resolved T2 MR relaxometry in situ was applied to study the hydration progress in HPMC matrix tablets using a 11.7 T MRI system. Two spin-echo based pulse sequences—one of them designed to specifically study short T2 signals—were used.ResultsTwo components in the T2 decay envelope were estimated and spatial distributions of their parameters, i.e. amplitudes and T2 values, were obtained. Based on the data, five different regions and their temporal evolution were identified: dry glassy, hydrated solid like, two interface layers and gel layer. The regions were found to be separated by four evolving fronts identified as penetration, full hydration, total gelification and apparent erosion.ConclusionsThe MRI results showed morphological details of the hydrating HPMC matrices matching compound theoretical models. The proposed method will allow for adequate evaluation of controlled release polymeric matrix systems loaded with drug substances of different solubility.
Highlights
Structural Characteristics and Analysis of Matrix SystemsHydrophilic matrix systems are often used for controlled release (CR) of drugs
Hydroxypropylmethyl cellulose (HPMC) is one of the best-known excipients used for the preparation of a CR polymeric matrix systems (1)
In our previous work we have reported on the observation of three regions in the swelling hydroxypropylmethyl cellulose (HPMC) matrices (19)
Summary
Structural Characteristics and Analysis of Matrix Systems. Hydrophilic matrix systems are often used for controlled release (CR) of drugs. The controlled release of an active pharmaceutical ingredient is obtained by the formation of a rubbery layer on the surface of the matrix. This layer acts as a barrier for inward liquid penetration and provides a controlled release of the dissolved drug. Hydroxypropylmethyl cellulose (HPMC) is one of the best-known excipients used for the preparation of a CR polymeric matrix systems (1). The well-defined structure, the wide range of polymer types and the consistency of the samples make HPMC the polymer of choice for CR systems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
