Co-delivery of isotretinoin and clindamycin by phospholipid-based mixed micellar system confers synergistic effect for treatment of acne vulgaris.

BACKGROUND: The combination therapy of Isotretinoin (ITR) and antibacterial formulations administered through topical route suffer from several limitations including reduced therapeutic efficacy and low patient-compliance. EXPERIMENT: The present study aimed to develop biocompatible lipid-based mixed micelles of ITR in combination with Clindamycin phosphate (CLIN) employing self-assembly method to improve its skin delivery, photostability, biocompatibility and pharmacodynamic efficacy. RESULTS: The MTT assay and cellular uptake studies showed non-cytotoxic effect to HaCat cell lines. The zone of inhibition studies conducted in Propionibacterium acnes provides the first literature evidence to support the antimicrobial property of Isotretinoin and Tretinioin. The nano-sized carriers offered (19.3 ± 1.03 nm particle size with -3.12 mV zeta potential) enhanced permeation, skin retention, pre-clinical efficacy and significant skin biocompatibility. The testosterone-induced acne model proved superior pharmacodynamic efficacy of lab developed formulation vis-à-vis marketed products of both the drugs. The results were further confirmed by the histopathological studies of respective skin samples treated with different formulations. CONCLUSION: The lab developed lipid-based micellar formulation of ITR and CLIN offers a better strategy for the combined delivery of unstable molecules like ITR and CLIN in acne management.

Nano-lipoidal carriers of tretinoin with enhanced percutaneous absorption, photostability, biocompatibility and anti-psoriatic activity.

Tretinoin (TRE) is a widely used retinoid for the topical treatment of acne, psoriasis, skin cancer and photoaging. Despite unmatchable efficacy, it is associated with several vexatious side effects like marked skin erythema, peeling and irritation, eventually leading to poor patient compliance. Its photo-instability and high lipophilicity also pose challenges in the development of a suitable topical product. The present study, therefore, aims to develop biocompatible lipid-based nanocarriers of TRE to improve its skin delivery, photostability, biocompatibility and pharmacodynamic efficacy. The TRE-loaded liposomes, ethosomes, solid lipid nanoparticles (SLNs) and nanostructured lipidic carriers (NLCs) were prepared and characterized for micromeritics, surface charge, percent drug efficiency and morphology. Bioadhesive hydrogels of the developed systems were also evaluated for rheological characterization, photostability, ex vivo skin permeation and retention employing porcine skin, and anti-psoriatic activity in mouse tail model. Nanoparticulate carriers (SLNs, NLCs) offered enhanced photostability, skin transport and anti-psoriatic activity vis-à-vis the vesicular carriers (liposomes, ethosomes) and the marketed product. However, all the developed nanocarriers were found to be more biocompatible and effective than the marketed product. These encouraging findings can guide in proper selection of topical carriers among diversity of such available carriers systems.