In vitro characterization studies of self-microemulsified bosentan systems

AbstractContext: Bosentan is a poorly soluble drug and pose challenges in designing of drug delivery systems.Objective: The objective of this study is to enhance the solubility, dissolution and shelf-life of bosentan by formulating it as S-SMEDDS capsules.Materials and methods: Solubility of bosentan was tested in various liquid vehicles such as oils (rice bran and sunflower), surfactants (span 20 and tween 80) and co-surfactants (PEG 400 and propylene glycol) and microemulsions were developed. Bosentan was incorporated into appropriate microemulsion systems which were previously identified from pseudo ternary phase diagrams. Bosentan-loaded SMEDDS were evaluated for drug content, drug release, zeta potential, and droplet size. The selected liquid SMEDDS were converted into solid SMEDDS by employing adsorption and melt granulation. Solid SMEDDS were characterized for micromeritics and evaluated for drug content, drug release, and shelf-life.Results: Isotropic systems R5, R13, S5, and S13 with submicron dr...