Formulation and evaluation of the novel herbal antibacterial gel to the treatment of cutaneous burn infections

Due to the rapid development of antibiotic resistance, the strong need for alternative strategies to tackle this problem is inevitable. The objective of this study was to prepare and evaluate the antibacterial effects of a pharmaceutical gel containing herbal extracts including Lawsonia inermis (henna) and Matricaria chamomilla. Using hydroxypropyl methylcellulose (HPMC), carboxymethylcellulose (CMC), and propylene glycol (PEG), the pharmaceutical gel was formulated and the physical properties of the formulation were specified at 37 ± 2°C. The total phenolic content (TPC) of extracts was determined using the Folin–Ciocalteu method and expressed as mg gallaic acid (GA) per gram extract (Ex). The release of the polyphenol compounds from the optimum formulation was investigated using the Franz cell device. Eventually, the disc diffusion method was used to evaluate the antibacterial activity of optimum formulation against the two pathogenic bacteria strains Staphylococcus aureus and Pseudomonas aeruginosa. The results showed that the optimum formulation was stable at least for 3 months. The TPC of the aqueous extract of henna leaves, the hydroalcoholic extract of chamomile flowers, and the optimum formulation was 57.8, 181.08, and 202.75 mg GA/g Ex, respectively. Nearly 80% of the phenolic compounds in the optimum formulation were released over 4 h. The phenolic compounds have inhibitory effects on the growth of S. aureus and P. aeruginosa. On the basis of this finding, the formulation had excellent stability, viscosity, homogeneity, extrudability, and antibacterial activity which can be employed as a topical pharmaceutical gel in cutaneous burn infection treatment.