PubMed Health⌕ Search

Biomedical subjects

A A Karnachi

Publications and source records attributed to A A Karnachi.

2 recordsLinked to original sources
PubMed2000

Stability characterization of controlled release coprecipitates and solid dispersions.

The present study was conducted to determine the effects of ageing at exaggerated storage conditions on controlled release tablets prepared with indomethacin-Eudragit((R)) coprecipitates (CPs) and solid dispersions (SDs). CPs and SDs compressed as tablets were stored at -20, 4, 37, 45, 55, 37 degrees C/11% RH, 37 degrees C/51% RH and 37 degrees C/91% RH. The samples were analyzed over a period of six months for their dissolution, crystalline reversion and thermal changes. Samples stored at extremely low temperatures, higher temperatures and humidity conditions exhibited a significant decrease in dissolution rates. However, no significant change in the release rates was observed for samples stored at 4 degrees C. The degree of crystallinity increased over a period of time as confirmed by X-ray diffractometry. DSC data demonstrated that indomethacin exists in two polymorphic forms, Form I (mp 160-161 degrees C) and Form II (mp 153-154 degrees C). CPs showed an endotherm of Form I, whereas SDs showed a mixture of Form I and II.

Acrylic Resins↗
PubMed1997

Comparative evaluation of the severity of gastric ulceration by solid dispersions and coprecipitates of indomethacin.

The ulcerogenic activity of indomethacin was studied in rats following single and chronic doses of indomethacin in the form of pure drug, solid dispersions and coprecipitates. Each formulation was administrated as a suspension in a 2% methylcellulose solution. Gastrointestinal ulceration was assessed, four hours after a single dose and 24 hours following the last dose of a chronic four day dosing regimen, by counting the number of lesions and ulcers present. A rating scale was employed to evaluate the severity index. The coprecipitate formulation produced less severe ulceration than the solid dispersion and pure drug. This suggests that the severity of ulceration than the solid dispersion and pure drug. This suggests that the severity of ulceration may be related to the preparation methodology and drug release kinetics.

Animals↗