Abstract
A two level factorial design approach was applied to the formulation of prolonged release phenylpropanolamine tablets using three factors: Ethylacrylate-methyl meth-acrylate co-polymer (Eudragit NE-40D) concentration, Microcrystalline cellulose (Avicel PH102) addition to the tablets formula, and the milling of the granulations before compression. The release rate of the drug was the measured parameter. The rate of drug release was mainly affected by the level of the Eudragit. Avicel promotes the release of the drug, specially at low Eudragit level concentrations. Tablets prepared from unmilled lots showed slower drug release than the corresponding lots of milled granules.