Nanosized ethosomes-based hydrogel formulations of methoxsalen for enhanced topical delivery against vitiligo: formulation optimization, in vitro evaluation and preclinical assessment.

The present investigation aimed for the development and characterization of ethosomes-based hydrogel formulations of methoxsalen for enhanced topical delivery and effective treatment against vitiligo. The ethosomes were prepared by central composite design (CCD) and characterized for various quality attributes like vesicle shape, size, zeta potential, lamellarity, drug entrapment and drug leaching. The optimized ethosomes were subsequently incorporated int Carbopol® 934 gel and characterized for drug content, rheological behavior, texture profile, in vitro release, ex vivo skin permeation and retention, skin photosensitization and histopathological examination. Ethosomes were found to be spherical and multilamellar in structures having nanometric size range with narrow size distribution, and high encapsulation efficiency. Ethosomal formulations showed significant skin permeation and accumulation in the epidermal and dermal layers. The fluorescence microscopy study using 123 Rhodamine exhibited enhanced permeation of the drug-loaded ethosomes in the deeper layers of skin. Also, the developed formulation showed insignificant phototoxicity and erythema vis-à-vis the conventional cream. The results were cross-validated using histopathological examination of skin segments. In a nutshell, the ethosomes-based hydrogel formulation was found to be a promising drug delivery system demonstrating enhanced percutaneous penetration of methoxsalen with reduced phototoxicity and erythema, thus leading to improved patient compliance for the treatment against vitiligo.

Topical treatment in vitiligo and the potential uses of new drug delivery systems.

Vitiligo is a psychologically devastating condition. Topical therapy is employed as first-line treatment in localized vitiligo. Currently, several topical agents are available in many forms viz. methoxsalen (solution and cream), trioxsalen (solution), corticosteroids (gel, cream, ointment and solution) and calcineurin inhibitors (ointment and cream). Although topical therapy has an important position in vitiligo treatment, side-effects or poor efficacy affect their utility and patient compliance. Novel drug delivery strategies can play a pivotal role in improving the topical delivery of various drugs by enhancing their epidermal localization with a concomitant reduction in their side-effects and improving their effectiveness. The current review emphasizes the potential of various phospholipid based carriers viz. liposomes, transferosomes, ethosomes, lipid emulsions, solid lipid nanoparticles and organogels in optimizing and enhancing the topical delivery of anti-vitiligo agents, whilst reducing the side effects of drugs commonly used in its topical treatment.