Novel delivery strategy: finasteride-loaded solid lipid nanoparticles for improved androgenetic alopecia therapy.

Androgenetic alopecia (AGA) is currently the most prevalent cause of hair loss on the scalp. The daily administration of finasteride (FINA) by oral route may lead to the development of numerous undesirable systemic side effects. However, commercially available dermal dosage forms are available only with minoxidil; few studies have claimed severe side effects. Our study deals with the development of solid lipid nanoparticles (SLNs) of FINA with a suitable combination of l-α-phosphatidylcholine (LPC) and -trimethyl chitosan (NTC) to overcome limitations along with good skin retention and hair growth. FINA-SLNs were developed using the ultrasonication technique and characterized further, along with hair growth observed in the animal model. The formulation NP7 showed the highest zeta potential value of -16.5 mV. The absence of the [double bond, length as m-dash]NH peak in the H-NMR spectra could be due to the protons attached, which have substantial exchangeability and result in a probable disappearance in the NMR spectra. The investigation showed the highest skin retention of 226.76 μg of FINA by NP7, along with a modest amount of FINA permeated (71.23 μg) during the study period of 18 h. The animal model using C57BL/6 mice showed a notable enhancement in hair covering and growth in Group IV, which received treatment without any visible cutaneous reaction on the skin. This outcome underscores the effectiveness and importance of the formulation developed using a suitable combination of LPC and NTC, which could be used to manage AGA effectively.