Development and evaluation of berberine-loaded bigel for the treatment of hyperpigmentation on B16F10 melanoma cell line

<b>Aim:</b> The aim of this study was to optimize, develop, characterize and evaluate a topical nanobigel (BG) formulation containing Berberine (BRB) that exhibits anti-melanogenic properties. <b>Materials &amp; methods:</b> The Berberine-loaded bigel (BRB@BG) formulation was prepared by homogenously mixing the optimized hydrogel and oleogel. BRB@BG was characterized <i>in vitro</i> and cytotoxicity study was conducted to evaluate its effects on murine skin melanoma B16F10 cell lines. <b>Results:</b> The optimized BRB@BG exhibited uniform texture with nanometric size, desirable spreadability and extrudability, suitable for topical applications. Cytotoxicity studies revealed that BRB@BG had a lower IC₅₀ value (4.84 μg/ml) on B16F10 cell lines compared with drug alone. <b>Conclusion:</b> In conclusion, the developed BRB@BG formulation showed good potential as safe and effective topical treatment for hyperpigmentation. Hyperpigmentation is a common skin disease in which the melanin content becomes abnormally high. The existing treatment options are associated with side effects and therefore research is being aimed to develop a topical nanoformulation based on natural compounds. Berberine (BRB) is one such natural compound that is known to inhibit the production of melanin in skin. This study was aimed to develop a bigel formulation of BRB that can be applied on skin, which can treat the hyperpigmentation and is safe. The developed nanomedicine was found to have all good properties of a topical formulation and was more effective than the drug alone. Various studies on animals were conducted to assess its safety and it was found that the formulation did not show any toxicity to the skin. Berberine, an isoquinoline alkaloid is reported to have antimelanogenic effect but is associated with poor oral bioavailability. Berberine-loaded bigel (BRB@BG) was prepared by homogenously mixing the optimized hydrogel and oleogel. The prepared BRB@BG was characterized using <i>in vitro</i> methods, TEM and trinocular microscopy. Cytotoxicity study was conducted to evaluate the effects of BRB@BG on the murine skin melanoma B16F10 cell lines. Safety of the developed formulation was performed using Draize test followed by histopathology and <i>in ovo</i> irritation studies. The developed formulation showed all desirable properties of an ideal topical formulation. The IC₅₀ values obtained after cytotoxicity studies was found to be lower than the plain drug showing better efficacy. The developed formulation showed no toxicity in any of the safety evaluation test.