Development and Characterization of a Clotrimazole-loaded Bigel for Topical Drug Delivery

Bigel formulations are multifunctional two-phase systems that incorporate hydrogels and organogels in varying ratios, maximizing the functional advantages of the water and oil phases. Such a biphasic system addresses the drawbacks of monophasic gels, in which organogels enhance transdermal penetration while the hydrogel maintains adequate hydration of the stratum corneum.

A hydrogel system was dispensed by gradually adding Carbopol 940 into distilled water while maintaining uniform stirring. For the preparation of organogels, Span 20 and Span 80 were incorporated into olive oil at an elevated temperature (60°C) with constant agitation. The final hydrogel and organogel bases were homogenized in varying proportions to obtain bigel formulations. The formulation was evaluated for parameters such as spreadability, extrudability, swelling behaviour, drug content, in vitro drug release profile, stability testing, and antimicrobial assessment.

The formulations were comprehensively evaluated for physicochemical characteristics such as spreadability, extrudability, swelling behaviour, viscosity, drug content, and stability upon centrifugation. Among the prepared batches, B5 showed the highest drug release (94.1% at 8 h) and displayed significant antimicrobial activity, producing zones of inhibition ranging from 17.43 ± 0.04 mm to 36.33 ± 1.15 mm against the tested microbial strains. Stability studies demonstrated their physicochemical properties throughout the three-month accelerated stability study, indicating robustness.

Effective topical administration against Candida albicans was demonstrated by the optimal release, stability, and antifungal activity of B5 optimized clotrimazole bigel. With all factors considered, outcomes suggest bigel-based administration as a feasible approach for enhancing local clotrimazole therapy while retaining high patient acceptability.

Among the prepared batches, B5 showed the largest zone of inhibition (36.33 ± 1.15 mm) against Candida albicans, demonstrating the potential of the developed bigel as an effective topical treatment for cutaneous fungal infections.