Journal of

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Background and Aim: Shampoos are surfactant systems to clean hair and body. Two kinds of surfactants are generally used in shampoo formulations: anionic and amphoteric. These agents, especially anionic ones may cause skin irritation and dryness after bathing. So, using a simple and fast method to determine the types and concentrations of surfactants can help to choose a product with high efficacy and low side effects. This study was aimed to determine surfactant concentrations using potentiometric titration method. Methods: Ten hair and body shampoos were selected from Iran's market to determine concentration of anionic and amphoteric surfactants using potentiometric titration method with prepared standard solution. Results: All formulations contain both surfactants, but one formulation did not have the amphoteric one. Conclusion: When we want to choose a shampoo for irritated and dry skin, formulations with more amphoteric surfactant should be chosen because they are much milder on the skin in comparison with anionic surfactants. Potentiometric method which was described in this study is one of the easiest ways to find out which shampoo is suitable for each patient.

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The rapid advancement of nanotechnology has brought about a significant transformation in the cosmetic and dermatological industries and has paved the way for the development of nanoscale delivery systems with higher efficiency. Among these systems, nanoemulsions have gained a special place due to their very small droplet size, optical clarity, kinetic stability, and effective interaction with the skin. Their two-phase structure, consisting of immiscible water and oil phases stabilized by surfactants provides an efficient platform for the encapsulation and controlled release of hydrophilic and lipophilic active ingredients. Nanoemulsions improve bioavailability and enhance efficacy by increasing the solubility of compounds, protecting sensitive substances from degradation, and facilitating the penetration of compounds into deeper layers of the skin, and also, in many cases, helping to reduce skin irritation and systemic absorption. This study explains the physicochemical principles governing the behavior of nanoemulsions, including interfacial phenomena, surfactant selection criteria, and stability and instability mechanisms. The functional role of nanoemulsions in cosmetic formulations is also investigated in terms of moisturizing, anti-aging, photoprotection, and targeted skin treatment. The integration of nanotechnology with cosmetic formulation science introduces a new generation of safe, stable, and multifunctional products that canprovide improved skin function and greater consumer satisfaction.