The process yielded spherical microparticles with a narrow size distribution (27–60 and 36–56 µm for Eudragit L and Eudragit S microparticles, respectively). Upon incubation in acid medium (pH 1.2) for 2 h, the release of dipyridamole, cinnarizine, amprenavir, bendroflumethiazide, budesonide and prednisolone from both Eudragit microparticles was less than 10% of drug load and conformed with the USP specifications for enteric dosage forms. In contrast, more than 10% of the entrapped paracetamol, salicylic acid and ketoprofen were released. Multiple regression revealed that the drug's molecular weight was the most important factor that determined its extent of release in the acid medium, while its acid solubility and microsphere's size had minor influences
Alhnan, M, Cosi, D, Murdan, S, Basit A. Inhibiting the Gastric Burst Rrelease of Drugs from Enteric Microparticles: The Influence of Drug Molecular Mass and Solubility. J Pharm Sci. 2010:4576–4583. Correspondence to Abdul W. Basit, Department of Pharmaceutics, The School of Pharmacy, University of London, at email@example.com or 44-20-7753-5865.