Stability and bioavailability of diltiazem/polyethylene oxide matrix tablets

Abstract

The aim of this study was to prepare and evaluate in vitro and in vivo; Diltiazem-Hydrochloride (DTZ) in sustained-release matrix tablets. Stability of DTZ tablets prepared with polyethylene oxide (MWs 900 000, 4 000 000, and 8 000 000) with or without addition of electrolytes was carried-out for 1-month, under short-term storage at 40 °C/75% RH. Stability was evaluated by DTZ content, DSC and drug release using the Flow-Through Cell (USP # IV). The majority of stored tablets were stable for 1-month under short-term storage with respect to DTZ content and drug release. DSC curves of stored samples showed appearance of new exothermic peak after 1-month storage at 40 °C/75% RH, which was not observed after 5 years storage at room temperature. A selected formula was tested in vivo against reference product on eight healthy human volunteers. DTZ-plasma profiles were different between the two formulae. However, no statistically significant differences were detected between C, AUC and AUC. The two products were therapeutically in-equivalent, as 90% confidence intervals "T/R" were 88.82-205.76, 91.40-139.94, and 93.73-134.97 for C, AUC and AUC, respectively. This study highlighted possible differences observed between the two regimes frequently applied for stability testing.

Comparative in Vitro Dissolution Study on Metformin Market Products Using Different Dissolution Apparatuses

“…For many years, efforts have been made to minimize the number of in vivo studies required to approve a new molecule or a generic product. One of the approaches currently used is the in vitro (mainly dissolution) tests that act as a tool to predict drug product performance in vivo [1][2][3][4]. It is necessary to have precise and reproducible dissolution data resulting from physiochemically and hydrodynamically determined conditions to compare variability and reproducibility for in vitro dissolution data and to manage using such results as a replacement for in vivo bioavailability, bioequivalence testing and in vitro/in vivo correlations (IVIVC) [5].…”

Research of Stability of Swine’s Cryoliophilized Xenoderma Tablets

“…At high humidity, the stability of the tablets usually decreases, while the time of disintegration can increase or decrease. [1,9] Rise of air temperature and the solar activity also has a negative effect on the quality of tablets. Therefore, the tablets are stored at room temperature in a dry, lightprotected place.…”