Formulation and evaluation of an SLS-free polyherbal anti-dandruff shampoo containing Sapindus mukorossi, Azadirachta indica, Acacia concinna, Aloe vera, and Phyllanthus emblica

Heightened awareness among consumers regarding the adverse effects of synthetic chemicals in hair care products has driven growing interest in plant-based cosmetic formulations. Conventional anti-dandruff shampoos typically incorporate harsh anionic surfactants - most notably sodium lauryl sulfate (SLS) and sodium Lauretha sulfate - which, when used repeatedly over time, are known to cause scalp irritation, excessive dryness, allergic sensitization, and disruption of the scalp's natural acidic mantle. The present study was undertaken to develop a fully SLS-free, plant-derived anti-dandruff shampoo that delivers both clinical effectiveness and gentle tolerability. The formulation incorporated five well-established medicinal botanical ingredients: Sapindus mukorossi (Reetha) as a naturally derived foaming agent, Azadirachta indica (Neem) for its potent antifungal and antimicrobial properties, Acacia concinna (Shikakai) serving as a mild cleanser and hair conditioner, Aloe vera for scalp hydration and soothing activity, and Phyllanthus emblica (Amla) as an antioxidant-enriched hair tonic. Three experimental variants (F1, F2, and F3) were prepared with systematically varied concentrations of Reetha extract and Xanthan gum to identify the most suitable viscosity and performance profile. All three variants maintained a scalp-compatible pH in the range of 5.0 - 5.2. Formulation F2 exhibited the most favorable combination of properties, including optimal viscosity (2430 ± 18 cP), the greatest cleansing efficiency (82.6%), acceptable foam retention (75.0%), and superior cosmetic appeal. In antifungal testing against Malassezia furfur, a zone of inhibition of 17.0 ± 0.3 mm was recorded, confirming the therapeutic effectiveness of the formulation. Accelerated stability testing conducted at 40 °C / 75.0% RH over 30 days revealed no significant alterations in appearance, pH, viscosity, or microbial safety. Collectively, these findings support the developed shampoo as a viable, biodegradable, and consumer-friendly substitute for synthetic anti-dandruff products.