Formulation and Evaluation of Herbal Nanoemulgel Hair Dye Incorporating Hibiscus and Henna Extracts

The present study focuses on the formulation and evaluation of a herbal nanoemulgel hair dye using Hibiscus rosa-sinensis and Lawsonia inermis (henna) extracts as natural colouring agents. Conventional hair dyes may contain synthetic chemicals that can cause irritation or damage to hair and scalp. Therefore, herbal formulations are gaining attention as potential alternatives for natural hair colouring. Nanoemulgel combines the advantages of a nanoemulsion and a gel system, offering improved consistency, spreadability, and uniform application. In this study, aqueous extracts of hibiscus and henna were incorporated into a formulation containing coconut oil, Tween 20, acacia, glycerin, and hydroxypropyl methylcellulose (HPMC). The prepared formulations were evaluated for organoleptic properties, pH, physical stability, spreadability, sensitivity, and excipient compatibility. The formulations exhibited a reddish-pink colour, characteristic odour, good consistency, and homogeneity. The measured pH values ranged from 7.0 to 7.4, and no visible phase separation was reported during the observed storage period. The formulations also showed good spreadability, while no visible sensitivity reactions were reported under the preliminary evaluation conditions. The findings suggest that hibiscus–henna herbal nanoemulgel may have potential for application as a natural hair-colouring formulation. Further studies, including droplet-size analysis, comprehensive stability testing, and detailed safety evaluation, are required to establish its quality, performance, and suitability for practical use.