title: Phase characterization of indomethacin in adsorbates onto hydroxyethylcellulose.
abstract: The phase state and solubility of indomethacin in adsorbates onto hydroxyethylcellulose have been studied. The characterization of the adsorbates and their relevant physical mixtures was made by the use of DSC, X-ray diffractometry, FT-IR spectrometry, and solubility analysis. The drug-to-polymer ratio determines either a partial crystallization of the metastable alpha-form onto hydroxyethylcellulose surface or complete inhibition of indomethacin crystallization. Significantly improved drug aqueous solubility was achieved. A stable immobilization of indomethacin molecules onto hydroxyethylcellulose due to drug/polymer interactions can be assumed. The changed indomethacin phase state in the adsorbates remains stable for one-year storage at ambient conditions. These results could be of practical importance.
authors.affiliation: Faculty of Pharmacy, Medical University of Sofia, Bulgaria. sbogdanova@pharmfac.acad.bg
authors.forename: Svetla
authors.initials: S
authors.lastname: Bogdanova
authors.forename: Elka
authors.initials: E
authors.lastname: Bontcheva
authors.forename: Nadka
authors.initials: N
authors.lastname: Avramova
mesh_terms: D000327:Adsorption; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D003460:Crystallization; D004337:Drug Carriers; D004339:Drug Compounding; D004355:Drug Stability; D007213:Indomethacin / Q000737:chemistry*; D044367:Phase Transition; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004337:Drug Carriers; D002482:Cellulose; C002283:hydroxyethylcellulose; D007213:Indomethacin