Olmesartan Medoxomil-Loaded Niosomal Gel for Buccal Delivery: Formulation, Optimization, and Ex Vivo Studies

Objectives: Olmesartan medoxomil (OLM) is a low bioavailability antihypertensive drug. This study aimed to prepare and optimize an OLM niosomal gel and investigate drug permeation via a chicken buccal pouch. Materials and Methods: OLM-loaded niosome were prepared using a film hydration technique. The vesicle size, zeta potential, entrapment efficiency, and percentage cumulative drug release of niosome were evaluated. The niosomes were incorporated into a Carbopol 974P (1.5% w/v) ) gel, and the drug permeability of the niosomal gel was evaluated. The formulations of the niosomal gel were optimized using the Box-Behnken design. The optimized formulation was further characterized by transmission electron microscopy (TEM) and Fourier transform infrared radiation analysis. Results: The particle size and zeta potential of the optimized niosomal formulations were 296.4 nm and-38.4 mV, respectively. Based on TEM analysis, the niosomes were found to be spherical in shape. The permeability, flux, and permeability coefficient of the optimized niosomal gel were 0.507 mg/cm2, 2 , 0.083 mg/cm2 2 x hour, and 041 cm/hour, respectively. Histopathological evaluation revealed that the niosomal gel had better permeability than the OLM gel. Conclusion: Based on the results of the OLM niosomal gel, it can be concluded that the formulation can be beneficial in increasing bioavailability, resulting in better therapeutic efficacy.