Neem and Lemon Oil-Based Herbal Surface Cleaners: Formulation Approaches, Sporicidal Efficacy, and Surface Compatibility

Neem (Azadirachta indica) oil and lemon (Citrus limon) essential oil are attractive botanical actives for environmentally friendly surface cleaners due to their reported antimicrobial activity and biodegradability. This review synthesizes formulation strategies such as emulsions, nanoemulsions, and encapsulation that enhance delivery of hydrophobic oils in aqueous systems, summarizes available evidence on sporicidal and sporostatic activity of botanical and essential oil systems, evaluates surface compatibility issues across common substrates, and outlines standardized testing needed to support sporicidal claims. Gaps in mechanistic understanding and regulatory challenges are highlighted, and best-practice formulation and validation recommendations are provided for researchers and formulators.