Design and Optimization of Brimonidine-Embedded Hydrogel: In vitro and in vivo Characterization

Background: Topical alpha agonists approved by the FDA are used to treat rosacea. Because of its potent vasoconstrictor properties, brimonidine tartrate topical gel (0.33%) efficiently reduces erythema. The aim of this investigation was to develop and optimize a hydrogel containing brimonidine for topical application. Materials and Methods: Different gelling agents were used in variable amounts to generate gel formulations loaded with brimonidine tartrate. Following the evaluation of the preliminary batches, the One Factor at a Time (OFAT) design was used for optimization. An optimized batch of Gel was evaluated for pH, washability, homogeneity, viscosity, %Drug release and skin irritation study. Results and Discussion: Among the diverse polymers considered, the obtained results highlight Carbopol 934 was chosen for its stability, gel strength and consistent drug content in the dispersion medium. An optimization study revealed that the concentration of Carbopol 934 played a crucial role in formulation development, viscosity and in vitro drug release. Conclusion: Carbopol was chosen as a gelling agent for optimisation based on the preliminary investigation. The optimized batch exhibited desirable characteristics in terms of both drug release and viscosity. Further, the evaluation of the prepared gel confirmed the desirable properties. Additionally, a skin irritation study confirmed the suitability of the application of the gel.