Preparation and analgesic activity of Eudragit RS100 microparticles containing diflunisal.
Two different techniques, the quasi-emulsion solvent diffusion method and spray drying that provide polar and nonpolar preparation environments, were used to prepare microspheres from Eudragit RS100 (RS) (acrylic/methacrylic copolymer) incorporating the nonsteroidal anti-inflammatory drug diflunisal. The effects of pH on the preparation medium and drug/polymer ratio on production yield and drug incorporation, as well as on the in vitro drug release at pH 1.2 and 6.8 from tabletted microparticles, were evaluated. The drug-polymer interactions and the effect of diflunisal incorporation in the polymer matrix on drug crystallinity have been evaluated by using differential scanning calorimetry, IR and ultraviolet spectroscopy, x-ray diffraction, and microscopy analysis. A preliminary biological assay confirmed that diflunisal maintains its analgesic activity after intraperitoneal administration to rats.
Dipartimento di Scienze Farmaceutiche, Università degli Studi di Catania, Italy. pignatel@mbox.unict.it
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D000180:Acrylic Resins / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000698:Analgesia; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000493:pharmacokinetics; D002152:Calorimetry, Differential Scanning; D004061:Diflunisal / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D006863:Hydrogen-Ion Concentration; D008081:Liposomes; D008297:Male; D008433:Mathematics; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010146:Pain / Q000188:drug therapy*; D010147:Pain Measurement; D051381:Rats; D017207:Rats, Sprague-Dawley; D013055:Spectrophotometry, Infrared
D000180:Acrylic Resins; D000894:Anti-Inflammatory Agents, Non-Steroidal; D008081:Liposomes; C050528:Eudragit RS; D004061:Diflunisal