ON THE INTERACTION BETWEEN RIFAMPICIN AND MACROMOLECULES 1- POLYSORBATES

Document Type : Original Article

Authors

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

Abstract

The permeation rates of rifampicin through a standard cellophane membrane were investigated in presence of different polysorbates. The surfactants were used in a concentration range of 0.2-0.6% w/v. The data revealed that as the surfactant concentration was increased, the diffusion rates were found to be decreased. This was explained on the basis that as the surfactant concentration was increased, the partial volume fraction was consequently increased and a large amount of rifampicin was incorporated inside the micellar core. These incorporated rifampicin molecules are not ready to permeate through the membrane. The Langmuir plots as well as spectrophotometric analysis indicate that a complex formed between rifampicin and the tested polysorbates. This complex is not ready, also, to penetrate through the membrane. It was found that the limiting adsorption capacities of surfactants were almost the same. This was explained on the basis that they are characterized by having the same number of oxyethylene unites.