Application of D-optimal Mixture Design for Development and Optimization of Olmesartan Medoxomil Loaded SMEDDS

Abstract

Background: Olmesartan medoxomil is an angiotensin II receptor blocker antihypertensive drug which has low oral bioavailability because of poor aqueous solubility. Objective: The objective of present research is development and optimization of Olmesartan medoxomil loaded self-microemulsifying drug delivery system by D-optimal mixture design to improve its dissolution rate. Methods: Solubility of Olmesartan medoxomil was determined in different oils, surfactants and co-surfactants. Pseudo ternary diagram was constructed for identification of self-microemulsification region. The D-optimal mixture design was employed for optimization of SMEDDS formulations wherein the factors optimized were the concentration of oil (X1), surfactant (X2) and co-surfactant (X3) and the response were globule size (Y1) and dissolution rate (Y2). Developed self-microemulsifying drug delivery system were further assessed for self-emulsification time, drug loading capacity, transparency, globule size, in vitro dissolution and comparative in vitro dissolution testing of optimized formulation with pure medicament and commercially available product. Results: The application of D-optimal mixture design resulted in 14 batches out of which F-5 was found to be the optimized batch which contained Olmesartan medoxomil (20 mg), Capmul MCM EP (23% v/v), Kolliphore EL (49% v/v) and Transcutol P (28% v/v) having globule size of 105 nm, 94.7% dissolution within 30 minutes. In vitro dissolution rate of the drug from SMEDDS was appreciably higher than that of pure drug and marketed product. Conclusion: Olmesartan medoxomil self-microemulsifying drug delivery system was successfully developed and this approach could prove to be suitable for improvement of dissolution rate of BCS II class drugs.

Preparation, In Vitro Characterization, and Evaluation of Polymeric pH-Responsive Hydrogels for Controlled Drug Release

“…Their absorbance values were measured at 257 nm by using a UV/Visible spectrophotometer (UV-2600i, Shimadzu) to quantify the drug content in the drawn samples. This allowed for determining the amount of drug dissolved in each formulation. − …”