title: Stability characterization of controlled release coprecipitates and solid dispersions.
abstract: 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.
authors.affiliation: Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA. Khan@cortex.ama.ttuhsc.edu
authors.forename: M A
authors.initials: MA
authors.lastname: Khan
authors.forename: A A
authors.initials: AA
authors.lastname: Karnachi
authors.forename: V
authors.initials: V
authors.lastname: Agarwal
authors.forename: S R
authors.initials: SR
authors.lastname: Vaithiyalingam
authors.forename: S
authors.initials: S
authors.lastname: Nazzal
authors.forename: I K
authors.initials: IK
authors.lastname: Reddy
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D011232:Chemical Precipitation; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004355:Drug Stability; D004356:Drug Storage; D007213:Indomethacin / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D012995:Solubility; D013607:Tablets; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D000180:Acrylic Resins; D000894:Anti-Inflammatory Agents, Non-Steroidal; D003692:Delayed-Action Preparations; D011109:Polymethacrylic Acids; D013607:Tablets; C038300:methylmethacrylate-methacrylic acid copolymer; D007213:Indomethacin