MICROENCAPSULATION OF THEOPHYLLINE

Document Type : Original Article

Authors

1 Department of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut, Egypt

2 Department of Chest, Faculty of Medicine, Assiut University, Assiut, Egypt

Abstract

Theophylline microcapsules were prepared using the solvent evaporation technique. Each of ethylcellulose (EC) and cellulose acetate butyrate (CAB) was used as a coating material. The adopted technique was simple and efficient. The drug release rate from CAB-coated microcapsules was slower than that from EC-coated ones. Increasing the coating polymer concentration, in the internal phase, from 10 to 20% leads to a decrease in the release rate of the drug. Increasing the CAB/drug ratio from 1:1 to 2:1 leads to a decrease in the release rate. Sealant treatment of EC-coated microcapsules was tried in an attempt to lower the drug release rate thereof. The sealant had a pronounced effect on the release rate. The effect was more enhanced by increasing the sealant concentration.
Three sustained release formulations of the microcapsules were prepared and orally administered to asthmatic patients. The drug serum levels revealed a sustained action of the tested formulations.