Topical finasteride dose evaluation for treatment of androgenetic alopecia using computer simulations

Summary Objective Our objective was to evaluate the absorption of finasteride administered by oral and topical routes for treatment of androgenetic alopecia, by means of computer simulations using the GastroPlus ® software. Material and methods In vivo plasma concentration profile of oral administration of finasteride 1 mg tablets from the literature was used in the software to build a compartmental pharmacokinetic model that was extrapolated to simulate topical administration of finasteride 0.25% solution in the scalp. Results were compared to literature and other drug concentrations (0.1% and 1%) were also predicted. Results Compared to literature data, predictive plasma curve from oral administration of finasteride 1 mg showed good correlation, R2=0.992, and Cmax=4.6769 ng/mL. Simulations of topical administration in the scalp for finasteride 0.25% solution showed good correlation, R2=0.908, and Cmax=0.04325 ng/mL when compared to literature data. Topical administration was also simulated at concentrations 0.1% and 1%, both with low plasma concentrations. Conclusion The results obtained in this study suggest that topical finasteride is a potential treatment for androgenetic alopecia in the concentrations analyzed using computer simulations in GastroPlus ®.