Targeted clindamycin delivery to pilosebaceous units by chitosan or hyaluronic acid nanoparticles for improved topical treatment of acne vulgaris.

We developed chitosan or hyaluronic acid nanoparticles to entrap clindamycin and evaluated for the first time the impact of these two polymeric nanosystems on the targeted drug delivery to the pilosebaceous units, considering the sebaceous characteristics of skin affected by acne. Chitosan and hyaluronic acid nanoparticles respectively presented diameters of 362 ± 19 nm and 417 ± 9 nm (PDI < 0.47), entrapped 42 % and 48 % of the clindamycin content (drug loading of 8.8 % and 0.5 %) and had opposite surface charges (+27.7 ± 0.9 mV and -30.2 ± 2.7 mV). Although only the hyaluronic acid nanoparticles showed increased deposition of the drug into the pilosebaceous structures, both nanoparticles revealed enhanced targeted delivery of clindamycin to these structures as compared to commercial formulation (53 ± 20 % and 77 ± 9% of the total drug that penetrated the skin was found on the pilosebaceous units from, respectively, chitosan and hyaluronic acid nanoparticles). Remarkably, the "targeting potential" of the nanoparticles was more pronounced when the skin was pretreated to simulate a sebaceous condition. In conclusion, both polymeric nanocarriers targeted drug delivery to the pilosebaceous structures at different extensions and, in the case of oily skin conditions, such targeting was increased.