Methodologies to Evaluate the Hair Follicle-Targeted Drug Delivery Provided by Nanoparticles

The document reviews various methodologies for evaluating the effectiveness of nanoparticle-based drug delivery to hair follicles. It highlights the use of porcine skin as a model due to its similarity to human skin. The document discusses several methods for evaluating drug delivery, including differential stripping, which showed that chitosan nanoparticles doubled the minoxidil accumulation in hair follicles compared to a control solution. It also introduces the "follicular targeting factor", a ratio to compare a formulation's potential for targeting hair follicles. The document emphasizes the importance of the follicular route for drug penetration, as shown by faster and more significant caffeine penetration via hair follicles compared to other routes. It also discusses the use of confocal laser scanning microscopy for high-resolution imaging of nanoparticle permeation through the skin. The document concludes that consistent test methodological conditions aligned with the skin's pathophysiology are crucial for obtaining reliable results.