Physicochemical characterization and release mechanism of a novel prednisone biodegradable microsphere formulation
✍ Scribed by Stefano Giovagnoli; Paolo Blasi; Maurizio Ricci; Aurelie Schoubben; Luana Perioli; Carlo Rossi
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 260 KB
- Volume
- 97
- Category
- Article
- ISSN
- 0022-3549
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✦ Synopsis
The aim of this work was the characterization of a new formulation of prednisone long-term controlled release biodegradable microspheres. Poly(DL-lactide-co-glycolide) (PLGA) polymers were used for MS preparation. A S/O/W solvent evaporation method was employed for prednisone entrapment. The system was characterized by using UV spectrophotometry, particle sizing, scanning electron microscopy, differential scanning calorimetry, X rays diffractometry, and microRaman spectroscopy. The release mechanism was studied by fitting Weibull, Peppas, Higuchi, and zero order kinetic models. The microspheres (MS) showed a good encapsulation efficiency and morphology, a suitable size and long-term release profile. Burst release was seen to depend on crystalline prednisone distributing close to the MS surface, and no particular prednisone-polymer interaction occurred. Weibull and Peppas were the best fitting models. Prednisone was released from PLGA MS following a Fickian diffusion and case II transport for higher molecular weight (MW) polymers, and a more complex mechanism involving solubilization, diffusion, and erosion, for low MW PLGA. Fully characterized PLGA MS may represent a good tool for a long-term delivery of prednisone in low-dose regimen treatments.