ORIGINAL ARTICLE The physicochemical, safety and antimicrobial properties of Phyllanthus amarus herbal cream and ointment Tolulope O. Ajala 1 • Mbang N. Femi-Oyewo 2 • Oluwatoyin A. Odeku 1 • Oluwasanmi O. Aina 3 • Adebowale B. Saba 4 • Olayinka O. Oridupa 4 Received: 8 October 2015 / Accepted: 22 December 2015 Ó The Korean Society of Pharmaceutical Sciences and Technology 2015 Abstract The ethanol extract of Phyllanthus amarus (Schum and Thonn), a plant of ethnomedicinal importance, was formulated into herbal cream and ointment and eval- uated using physicochemical, safety and antimicrobial properties. The extract was obtained by maceration and the antimicrobial properties tested on clinically isolated pathogenic bacteria (Staphylococcus aureus and Pseu- domonas aeruginosa) and dermatophytes (Trichophyton rubrum and Candida albicans) using established methods. Cream and ointment formulations containing 1–10 % w / w extract was prepared and 4 % w / w humectant (glycerin) was incorporated into the cream while 5 % w / w surfactant (cetomacrogol 1000) was incorporated to the ointment. The results showed that the pH of the formulations was acidic and the viscosity ranged from 1250 to 4950 cP for oint- ments and 570–1233 cP for creams. The presence of humectant and surfactant significantly (p \ 0.05) reduced the viscosities of the formulations. The results of dermal irritation showed negligible irritation index while sub- chronic toxicity tests showed that the formulations did not cause any visible lesions in the skin of the animals after application for twenty-one days. The in vitro antimicrobial properties of formulations were concentration-dependent with the creams showing higher activity. Furthermore, the in vivo activity of the cream on S. aureus showed increased antibacterial activity with increase in extract concentration and humectant presence. The herbal cream and ointment of Phyllanthus amarus extract had acceptable physicochemi- cal and safety profiles with significant (p \ 0.05) in vitro and in vivo antimicrobial activity. Thus, the formulations could be useful in the treatment of skin infections instead of using the extract for bathing and rubbing. Keywords Phyllanthus amarus Á Cream Á Ointment Á Physicochemical Á Safety Á Antimicrobial property Introduction Pharmaceutical semi-solid preparations are topical prod- ucts intended for application to the skin or accessible mucous membrane to provide local or sometimes systemic effects at application sites (Betageri and Prablu 2002). Topical agents like creams and ointments are more attractive than oral therapy because they reduce the potential for systemic adverse reactions. They are also suitable for self-administration of medication since no specialized appliances or personnel are required leading to improved patient compliance. Efficacy is also achieved by lower total daily dosage of drug since it is applied directly to the affected area (Martin et al. 2005). Creams are non-greasy viscous systems with opaque appearance in contrast to ointments which are more viscous and translucent (Buhse et al. 2005). The base for creams is usually an oil-in-water emulsion or aqueous microcrys- talline dispersion of long-chain fatty acids or alcohols that & Tolulope O. Ajala tolulola1721@gmail.com 1 Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria 2 Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Olabisi Onabanjo University, Sagamu, Nigeria 3 Department of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria 4 Department of Veterinary Physiology, Biochemistry and Pharmacology, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria 123 Journal of Pharmaceutical Investigation Online ISSN 2093-6214 DOI 10.1007/s40005-015-0226-8 Print ISSN 2093-5552