Formulation and Evaluation of Microemulsion for Topical Drug Delivery

Abstract

As with the improvement in the field of antibiotics, the bacteria are also getting stronger and undergoing mutation to survive and eventually develop resistance to various antibiotics. A similar situation is experienced by patients with acne. So, to provide some relief, the study was carried out to find an effective combination of phytoconstituents for acne. The study was aimed to evaluate the efficacy of cinnamaldehyde, berberine, and piperine against Staphylococcus epidermidis and Propionibacterium acnes. The optimization was carried out using a central composite design with Oilmix, Smix, and water as independent variables whereas droplet size, PDI, and Viscosity were considered as dependent variables. The droplet size, PDI, and viscosity of the optimized formulation, CA-BER-ME, were found to be 67.81 ± 4.21 nm, 0.347 ± 0.009, and 36.5 ± 1.85 cPs, respectively. The prepared CA-BER-MEGel was characterized for parameters such as viscosity and pH, which were found to be 14097 ± 668 cPs, and 5.94 ± 0.18. The in vitro drug release and ex vivo permeation of CA-BER-ME was assessed in comparison with the drug suspension gel. Upon comparison, the prepared formulations, F1, F2, and F3 exhibited significant improvement in terms of drug release and permeation as compared to drug-loaded suspension gel. Then the antiacne potential of the CA-BER-ME-Gel was analyzed on the animal model and the thickness of the ear pinna of rat was measured. It was found to be least for the clindamycin gel (30.18 ± 13.94 %) followed by F-3 (41.85 ± 8.83 %), F-2 (55.18 ± 12.76 %), and F-1 (115 ± 7.27 %). Animals treated with the developed formulations showed significantly better antiacne potential (p lt 0.0001) as compared to the animals labeled with disease control.The skin irritation study indicated that F3 with higher amount of cinnamaldehyde produced irritation. Hence based on all the results and efficacy, F2 was selected as the final formulation with sufficient efficacy against S. epidermidis and P. acnes with no signs of irritation.