Preparation and In-Vitro Evaluation of Prolonged Release Tablets of Pheniramine Aminosalicylate

Prolonged release tablets of pheniramine aminosalicylate were prepared from co-precipitates of the drug in different types of Eudragit. The hardness of the tablet had a pronounced effect on the release rate of the drug. Tablets (500 mg, hardness 13 kg) and 375 mg tablets (hardness 6.5 kg) prepared from the co-precipitates containing 15% of the drug in Eudragit L 100, and 20% of the drug in Eudragit S 100 respectively, showed release rate patterns that were in agreement with Lang primary requirements for drug release from sustained release tablets.

Tablets (500 mg) prepared from the co-precipitates containing 15% of the drug in Eudragit L 100 or Eudragit S 100 and 375 mg tablets containing 20% of the drug in Eudragit S 100 showed release rate patterns that were best described by Higuchi equation, indicating that a diffusion controlled mechanism was mainly operative.