Development and Characterization of Micro- and Nano-emulsion-based Moisturizer Formulations with Polyherbal Extracts

Introduction: Herbal-based skincare products are increasingly favored for their multifunctional properties and minimal side effects. This study aimed to develop and evaluate polyherbal facial moisturizers containing Camellia sinensis (white tea) and watermelon rind extracts, targeting acneprone and dry skin. Methods: Six oil-in-water emulsions were formulated using Phytomulse Almond or Olivem as emulsifiers. Physicochemical assessments included pH, spreadability, extrudability, moisture content, particle size, and zeta potential. Stability was monitored under various storage conditions. Antibacterial efficacy against Staphylococcus aureus and Staphylococcus epidermidis was assessed using the agar well diffusion method. FTIR analysis confirmed functional group integrity. Results: FM1–FM4 demonstrated skin-compatible pH (4.5–6.5), superior moisture content (up to 89.89%), and favorable spreadability, comparable to commercial standards. These formulations showed antibacterial activity with inhibition zones between 7.5 and 9.2 mm; FM1 exhibited the strongest response. Stability tests confirmed formulation homogeneity and consistent organoleptic features at room temperature. FTIR spectra validated the presence of polyphenolic and lipid-based active compounds. Discussion: The observed physicochemical performance and antimicrobial activity were significantly influenced by emulsifier type and formulation matrix. Phytomulse-based emulsions (FM1–FM4) enabled efficient bioactive delivery, whereas Olivem-based ones (FM5–FM6) showed weaker inhibition, likely due to compound entrapment. FTIR spectra and performance data confirmed the compatibility of white tea and watermelon rind extracts with emulsion integrity. Conclusion: Polyherbal moisturizers, especially FM1 - FM4, showed favorable pH, hydration, stability, and antibacterial properties, supporting their potential in acne-prone and dry skin care. Further in vivo and clinical evaluations are warranted to confirm their therapeutic effectiveness and user acceptability.