Topical Emulgels of Griseofulvin for Dermatophytosis: Current Trends, Characterization Techniques, and Future Prospects

Abstract

Dermatophytosis is among the most prevalent superficial fungal infections worldwide and has recently taken an epidemic-like course in tropical countries such as India, marked by chronic, recurrent and treatment-recalcitrant presentations and rising resistance to terbinafine and azole antifungals. Griseofulvin, the first orally effective antidermatophytic antibiotic, remains pharmacologically active against the causative dermatophyte genera (Trichophyton, Microsporum and Epidermophyton) but its clinical utility is limited by poor aqueous solubility (Biopharmaceutics Classification System [BCS] Class II behaviour), variable oral bioavailability, a prolonged treatment course and systemic adverse effects. Delivering griseofulvin directly to the site of infection through the skin could circumvent these limitations, but conventional topical vehicles such as creams and ointments provide inconsistent drug release and poor cosmetic acceptability. The emulgel — a biphasic system in which an oil-in-water or water-in-oil emulsion is dispersed within a hydrophilic or hydrophobic gelling network — has emerged as an attractive alternative because it combines the enhanced solubilisation capacity of an emulsion for lipophilic drugs with the favourable rheological, spreading and patient-acceptability profile of a gel. This review consolidates the current literature on topical antifungal emulgels, with particular emphasis on griseofulvin, and systematically describes the epidemiological rationale, the biopharmaceutical basis for topical delivery, formulation strategies (including nanoemulsion-, nanostructured-lipid-carrier- and microemulsion-based emulgels), and the physicochemical, rheological, in vitro, ex vivo and in vivo characterization techniques applied to such systems. Comparative evidence from marketed and investigational antifungal emulgels of terbinafine, luliconazole and clotrimazole is used to benchmark expected performance. Regulatory, scale-up and stability challenges are discussed, followed by future prospects including nanotechnology integration, quality-by-design optimisation and combination therapy approaches for recalcitrant dermatophytosis. The review is intended to provide a comprehensive reference framework for researchers developing griseofulvin-based topical delivery systems