Microencapsulation of semisolid ketoprofen/polymer microspheres.
Ketoprofen controlled release microspheres were prepared, by emulsion/solvent evaporation, at 15 degrees C, in order to avoid the formation of semisolid particles. An identical procedure was carried out at 60 degrees C to speed up the solvent evaporation and the formed semisolid microspheres were directly microencapsulated by complex coacervation and spray-dried in order to recover them as free flowing powder. Microspheres and microcapsules were characterized by scanning electron microscopy, differential scanning calorimetry, X-ray diffractometry, in vitro dissolution studies, and then used for the preparation of tablets. During this step, the compressibility of the prepared powders was measured. Microspheres and microcapsules showed compaction abilities by far better than those of the corresponding physical mixtures. In fact, it was impossible to obtain tablets by direct compressing drug and polymer physical mixtures, but microspheres and microcapsules were easily transformed into tablets. Finally, in vitro dissolution studies were performed and the release control of the tablets was pointed out. Microspheres were able to control ketoprofen release only after their transformation into tablets. Tablets containing eudragit RS were the most effective in slowing down drug release.
Palmieri
Giovanni
G
Dipartimento di Scienze Chimiche, Università di Camerino, Via S. Agostino 1, 62032 Camerino, Italy. gianfilippo.palmieri@unicam.it
Bonacucina
Giulia
G
Di Martino
Piera
P
Martelli
Sante
S
D000180:Acrylic Resins; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D002482:Cellulose / Q000031:analogs & derivatives; D004339:Drug Compounding; D004655:Emulsions; D005079:Excipients; D006244:Hardness; D007660:Ketoprofen / Q000008:administration & dosage*; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D012997:Solvents; D013607:Tablets
D000180:Acrylic Resins; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004655:Emulsions; D005079:Excipients; D012997:Solvents; D013607:Tablets; C050528:Eudragit RS; C013517:ethyl cellulose; D002482:Cellulose; D007660:Ketoprofen