Formulation of antimicrobial cream from the leaves and bark of Lannea welwitschii for wound healing.
Omotunde Okubanjo, Uzoma Nonso-Sylver, Sunday Ojo and Magaret Ilomuanya
1Department of Pharmaceutics and Pharmaceutical Technology,
Faculty of Pharmacy University of Lagos, Lagos, Nigeria.
Correspondence author: Omotunde Okubanjo
E-mail: mokubanjo@unilag.edu.ng; Phone: +234 – 803-714-7599
ABSTRACT
Background: Recently there has been a remarkable surge of interest in natural products and their applications in the cosmetic industry. Topical delivery of antimicrobials from natural sources like Lannea welwitschii is one of the approaches used to treat wounds due to its diverse clinical and pharmacological potentials.
Objectives: The aim of this study was to develop an oil-in-water cream formulation of the methanol extract of the leaves (LF) and bark (BF) of Lannea welwitschii (Hiern) Engl. (Fam. Anacardiaceae) for topical delivery in the treatment of wound infections.
Methods: The antimicrobial activity of the extract was investigated. The cream was formulated using fusion method. The oil-phase ingredients were slowly transferred into the aqueous phase at a temperature of 70 °C including the extracts 1%w/w with constant stirring. The formulations upon cooling were evaluated for pH, skin irritancy, viscosity, colour and odour. The stability of the cream over 30 days was investigated so also the wound healing properties of the cream was studied in 12 albino rats using the excision wound healing model.
Results: The minimum inhibitory concentration for both the leaf and bark extract was 4mg /ml. The extracts were most active against Proteus mirabilis with the leaf extract being more active than the bark extract. The extracts also had activity against Bacillus subtilis and Pseudomonas aeruginosa, with mean inhibition zone diameter ranging from 10-26mm. There was no antifungal activity observed. The four resulting cream formulations were homogenous, highly viscous, non-greasy, slightly acidic and non-irritant. The cream formulations from the leaf and bark extract were green and red respectively. There was no significant change in the evaluation parameters at 25 °C over a period of four weeks. The formulations appeared stable over the period. Statistical analysis showed that after a twenty-one day treatment on an excised wound, the two formulations showed comparable wound-healing with the standard (Cicatrin ). LF2 showed a significantly higher rate of wound closure (P < 0.05) than Bf2.
Conclusion: A standardized cream formulation of the extract from the plant Lannea welwitschii for wound healing was developed. The cream was found to be aesthetically acceptable, stable, therapeutically effective, and, hence has promising wound healing potentials in the health care industry.
Keywords: Lanneawelwitschii, methanol extract, wound-healing, antimicrobial cream formulation.