Formulation and optimization of captopril-loaded microspheres based compressed tablets: <i>in vitro</i> evaluation
Azeema Tayyab, Asif Mahmood, Hira Ijaz, Rai Muhammad Sarfraz, Nadiah Zafar, Zeeshan Danish
Abstract
The core objective of this work was to formulate compressed tablets containing captopril-loaded microspheres for controlled delivery. Captopril is rapidly absorbed orally and has a bioavailability of ∼75%. The duration of action after a single oral dose is 6–8 h. Due to its relatively short half-life, a controlled released captopril formulation would bring benefits to patients, including reduction in frequency of administration, increased patient compliance and effectiveness of treatment, reduction in plasma concentration fluctuations, as well as a reduction in side effects. Double emulsification technique accompanied by solvent evaporation was employed for manufacturing captopril-loaded microspheres. Developed polymeric carriers were characterized for particle size analysis, entrapment efficiency, DSC, TGA, XRD, EDS, SEM, swelling index, and release studies. Microspheres have displayed spherical geometry and a size within micrometric range. They have shown high encapsulation efficiency (95%) at polymer to drug ratio (1:5:5). All the ingredients were compatible with each other. Optimized formulation ST1 has depicted zero-order drug release.