in this study, attempts were made to evaluate the effect of various acrylic acid based carbopols on the release profile of a beta-adrenoreceptor blocking drug, propranolol hcl, from matrix-type tablets invitro. for this purpose, tablets containing 160 mg of propranolol hcl along with various amounts of carbopols 934 (c934), 971 (c971), 974 (c974) and pemulen (pem) were prepared using the wet gr...

Hydrophilic matrix tablets (matrices) for oral use are designed to hydrate on swallowing, and form a ‘gel’ layer of hydrated polymer at the tablet surface to control the rate of drug release during passage of the matrix through the gastrointestinal tract. During gastrointestinal transit, the matrices are reduced in size through surface erosion and dissolution. This reduces the probability of ex...

this paper reviews the use of texture analysis in studying the performance of hydrophilic matrices of highly soluble drugs and different types of excipients (i.e. water-soluble, water-insoluble and swellable, and water insoluble and non-swellable). tablets were prepared by direct compression, and their swelling and erosion in presence of these different excipients were assessed with the help of...

This paper reviews the use of texture analysis in studying the performance of hydrophilic matrices of highly soluble drugs and different types of excipients (i.e. water-soluble, water-insoluble and swellable, and water insoluble and non-swellable). Tablets were prepared by direct compression, and their swelling and erosion in presence of these different excipients were assessed with the help of...

This paper reviews the use of texture analysis in studying the performance of hydrophilic matrices of highly soluble drugs and different types of excipients (i.e. water-soluble, water-insoluble and swellable, and water insoluble and non-swellable). Tablets were prepared by direct compression, and their swelling and erosion in presence of these different excipients were assessed with the help of...

Oral controlled drug delivery has gathered tremendous attention over the years due to its many advantages over conventional dosage forms. Polymer-based matrices have become an integral part of the pharmaceutical industry. Hydrophilic matrices are capable of controlling the release of drug over an extended period of time. Hydrophilic polymers, especially the hydrophilic derivatives of cellulose ...

INTRODUCTION The percolation theory studies the critical points or percolation thresholds of the system, where one component of the system undergoes a geometrical phase transition, starting to connect the whole system.The application of this theory to study the release rate of hydrophilic matrices allows to explain the changes in release kinetics of swellable matrix type system and results in a...

Percolation theory has been applied in order to study the existence of critical points as well as the possibility to find a "combined percolation threshold" for ternary hydrophilic matrices prepared with HPMC, NaCMC, and theophylline. For this purpose, different batches of ternary as well as binary hydrophilic matrices have been prepared. Critical points have been found for binary hydrophilic m...

Serial (femtosecond) crystallography at synchrotron and X-ray free-electron laser (XFEL) sources distributes the absorbed radiation dose over all crystals used for data collection and therefore allows measurement of radiation damage prone systems, including the use of microcrystals for room-temperature measurements. Serial crystallography relies on fast and efficient exchange of crystals upon X...