Chitosan Nanoparticles as a Potential Drug Delivery System in the Skin: A Systematic Review Based on In Vivo Studies

Chitosan nanoparticles (ChNP) represent an interesting technological platform for drug delivery to the skin due to their mucoadhesive, nontoxic, and biodegradable characteristics, offering advantages in bypassing the stratum corneum and improving drug delivery in dermal administration. This systematic review analyzed the in vivo applicability of ChNP as a substance delivery system to the skin. A literature search was conducted in the databases PubMed, SciELO, and Lilacs using the keywords “nanoparticle,” “chitosan,” and “skin.” Inclusion criteria involved in vivo studies investigating the effects of topical use of these nanoparticles, published between 2013 and 2023, and comparing the nanoparticulate formulation with the free drug. The prevalence of studies conducted on animal models was 94.1%, while only 5.9% were performed on humans. The results suggest that ChNP formulations improved the delivery of therapeutic agents and demonstrated superior efficacy compared to formulations containing the free drug; they exhibited good permeability and tolerability, gradual release of the active molecule, and faster results with minimal adverse effects. Therefore, ChNP containing active substances for topical application emerges as a safe and effective platform with significant potential for drug delivery to the skin, opening new perspectives for their use in innovative formulations.