Formulation and evaluation of Anti-acne gel containing extracts of Curcuma longa L and Azadirachta indica A. Juss

Abstract

Background: Acne is a chronic inflammatory disease of the pilosebaceous units characterized by seborrhoea, formation of comedones, erythematous papules, and pustules and less frequently by nodules, cysts and scaring. Skin normal flora, Staphylococcus epidermis and Propionibacterium acnes have been implicated in the causation of acne. Antibiotics like clindamycin, tetracycline etc. and retinoids have been used and they are still the mainstay for the topical and systematic treatment of acne. However, these medications are associated with various side-effects such as allergy, local irritation, scaling, photosensitivity reaction, itching, peeling, redness. Also, the chronic use of these conventional drugs may produce other defects such as collagen vascular diseases as reported in acne patients on long term use of clindamycin gel. Aim of study was to formulate and evaluate herbal gel containing extracts of Curcuma longa and Azadirachta indica against P. acnes. Fresh leaves of A. indica were collected from the botanical garden in Entebbe, the rhizomes of C. longa (turmeric) were collected from the Kayunga district Uganda. The plants were authenticated by a taxonomist. Extraction and formulation were carried out in the pharmacy lab 2 of Makerere University while microbial evaluation was done in the microbiology lab of Veterinary medicine department, Makerere University. Extraction was done by maceration using ethanol 70% as a solvent and a gel was formulated. Quality control tests and antibacterial assay were done on the gel. The gel was also tested for safety. All extracts showed significant activity against P. acnes with A. indica extract having the higher zone of inhibition 29.0±1mm and C. longa at 23.3±1.5mm, p value 0.001. The best combination was of 75% A. indica and 25% C. longa with mean zone of inhibition of 34.3±1.2mm this was suggestive of synergism. Also, the best combination ratio of C. longa to A. indica is therefore 1:3. The formulated gel was non-irritant to the rat skin suggestive of safe to use. The combination of the extracts revealed possible synergistic activity at a ratio of 1:3 C. longa to A. indica hence is recommended for use against acne and a ratio of 1:1 is purely antagonistic. The formulation maintained its activity against P. acnes and it was non irritable to the rat skin.