Development and Evaluation of Dutasteride Nanoemulgel for the Topical Delivery against Androgenic Alopecia

Dutasteride is approximately three times more potent than finasteride in treating alopecia. For reducing systemic exposure to dihydrotestosterone (DHT), researchers have shown special interest in developing topical formulations for treating androgenic alopecia. Dutasteride emulsification may lead to good skin penetration and improved availability in different lipophilic skin environments.

This study aimed to encapsulate the drug into the lipidic carrier system for better local availability in the scalp skin, develop and evaluate nanoemulgel of dutasteride to ensure efficient topical administration, and perform the in-vivo activity of the developed gel for improved efficacy against alopecia.

Dutasteride-loaded nanoemulsion was prepared by a high-speed homogenizer, followed by thickening of the dispersion using Carbopol 934. Skin permeation and accumulation were investigated in the excised skin of male Swiss albino mice. The nanoemulgel was characterized based on pH, stress stability, viscosity, and hardness.

The optimized dutasteride-loaded nanoemulsion had a size of 252.33 ± 8.59 nm, PDI of 0.205 ± 0.60, and drug content of 98.65 ± 1.78%. Stress stability was performed was well observed in nanoemulsion formulation. Nanoemulgel evaluation results were as follows: pH 5-6 was desirable for topical application, hardness was 43 gm, and spreadability was 79 gm with in vitro release of nanoemulgel at 91.98% and permeation study at 13.67%.

The in vivo studies demonstrated the growth of newer hair follicles and increased hair diameter and length in dutasteride-loaded nanoemulgel-treated alopecia animals compared to the marketed sample and testosterone-treated group. Provided with the same and long-term storage stability, the developed formulation is supposed to offer a good option for the topical administration of dutasteride in treating androgenic alopecia.