Formulation Development and In-Vitro Characterization of Liquid and Solid Self Microemulsifying Drug Delivery System of Apremilast

Background: Most drugs are administered orally, but this route is limited for molecules with poor aqueous solubility, a key factor in achieving effective systemic drug concentrations for the desired pharmacological response. Many potential drugs face low solubility and dissolution rates, reducing absorption and low oral bioavailability. Objective: This study focused on developing and evaluating liquid (L-SMEDDS) and solid (S-SMEDDS) self-microemulsifying drug delivery systems for the poorly water-soluble Apremilast. The L-SMEDDS formulation used oleic acid (oil), Tween 80 (surfactant), and Transcutol HP (co-surfactant). S-SMEDDS were prepared via adsorption onto Aerosil as a solid carrier. L-SMEDDS were assessed for self-emulsification time, droplet size, zeta potential, PDI, transmittance, and drug content. S-SMEDDS evaluations included micromeritic properties, drug content, in vitro release, and structural analysis via SEM, DSC, and XRD. Result: The findings showed that solid SMEDDS significantly enhanced the dissolution rate of Apremilast, improving bioavailability by forming a microemulsion upon dilution in gastric fluids, which promotes better drug release. Conclusion: Overall, the results indicate that solid SMEDDS can significantly improve the solubility and dissolution profile of poorly soluble drugs, offering potential to enhance oral bioavailability and therapeutic efficacy.