Development of a self-microemulsifying drug delivery system of domperidone: In vitro and in vivo characterization

The main objective of this work was to prepare a self-micro emulsifying drug delivery system (SMEDDS) for enhancement of oral bioavailability of domperidone, a poorly water soluble drug. The solubility of the drug was determined in various vehicles. A pseudo ternary phase diagram was constructed to identify the self-micro emulsification region. The in vitro self-micro emulsification properties and droplet size analysis of SMEDDS were studied following their addition to water under mild agitation. Further, the resultant formulations were investigated for clarity, phase separation, globule size, effect of pH and dilutions (1:100, 1:500, 1:1000) and freeze-thaw stability. The optimized formulation, SMEDDS-B used for in vitro dissolution and bioavailability assessment, contained oil (Labrafac CC, 25 %, m/m), surfactant (Tween 80, 55 %, m/m), and co-surfactant (Transcutol (R), 20 %, m/m). The preliminary oral bioavailability of domperidone from SMEDDS was 1.92-fold higher compared to that of domperidone suspension in rats. The AUC(0-24) and c(max) values were 3.38 +/- 0.81 mu g h mL(-1) and 0.44 +/- 0.03 mu g mL(-1) for SMEDDS-B formulation in comparison with 1.74 +/- 0.18 mu g h mL(-1) and 0.24 +/- 0.02 mu g mL(-1) for domperidone suspension, suggesting a significant increase (p < 0.05) in oral bioavailability of domperidone from SMEDDSS.