Development and Pre-clinical Study of Anti-Allergic Cream Containing Dexamethasone and Chlorpheniramine

In this study, we aimed to develop and optimize an anti-allergic cream containing dexamethasone and chlorpheniramine using the design of experiments (DoE) method. The optimized product was investigated for its physicochemical properties and in vivo therapeutic effects in rabbits.

The creams were formulated using the simple mixing process, which was optimized by the Design Expert software. The products were then evaluated the properties such as pH, skin diffusion profile, short-term stability, qualitative, and assay, using the newly validated UV-Vis spectrophotoscopy quantitative method. In vivo efficacy tests in rabbits of the best products were compared with the marketed Phenergan^® (promethazine 2%).

The UV-Vis method used to simultaneously determine the amount of both dexamethasone and chlorpheniramine was successfully developed and validated. Using the DoE method, it was clear that the release profile of dexamethasone depended on the amount of sodium lauryl sulfate, propylene glycol, and DMSO. In contrast, only DMSO affected the release pattern of chlorpheniramine. The best formulation was optimized by the software. The product showed acceptable parameters in pH (5.7±0.1), short-term stability over 10 days, and skin diffusion profiles of 20.47±1.25% and 4.92±0.42% after 40 min for dexamethasone and chlorpheniramine, respectively. In addition, the product demonstrated no observable inflammatory response in the experimental animals. Also, it illustrated 2-fold better anti-allergic efficacy than the marketed product (i.e., 27.2 compared with 43.4 min in the recovery time).

We were successful in developing and optimizing an anti-allergic cream containing dexamethasone and chlorpheniramine. The best product satisfied all required parameters. Interestingly, our product showed higher efficacy than Phenergan^®. These results can be a background for further clinical trials.