DEVELOPMENT, CHARACTERIZATION AND ANTIBACTERIAL ACTIVITY OF GELS WITH EXTRACT OF Lippia turbinata AND Lippia alba

PÉREZ ZAMORA, CRISTINA; NUÑEZ, MARÍA BEATRIZ; CHIAPPETA, DIEGO

Córdoba

Congreso; 3ra Reunión Internacional de Ciencias Farmacéuticas; 2014

Universidad Nacional de Córdoba

Lippia alba and L. turbinata are claimed to possess antioxidant and antimicrobial activities. The aim of our work was to develop suitable formulations including ethanolic extract of these species. The plant extracts were obtained with ethanol 70% by percolation. Gels with carbopol® 934 and 940 at concentrations of 0.5% and 1% (w/v) were prepared. The extracts were dried at 37°C. Then, they were dissolved in a mixture of water, ethanol and propylene glycol to be incorporated into carbopol® suspension. Finally, they were gelled with triethanolamine. Gels without extracts were developed and no preservative agent was added. Physical evaluation (colour, odour, pH, appearance, viscosity, spreadability) of gels was tested. Determination of total phenolic content with the Folin-Ciocalteu reagent and antimicrobial activity by disc diffusion method were carried out. Hygienic control was performed according to Argentina Pharmacopeia 7° edition (FA7) for topical products. The gels were homogeneous, brown like the extracts and with slightly cytral, herbaceous smell. The pH value was 7.6 ± 0.1 for gels containing extract, and 5.3 ± 0.5 for gels without extracts. Consistency varied from fluid gel to moderately firm gel depending on the concentration of gelling agent used. Spreadability was good being better in gels with extracts. Viscosity values were between 280 and 10,000 centipose (cP) for gels with extracts, and over 10,000 cP for gels without extracts. The total phenolic content was 4.28 ± 0.37 mg/g. All gels presented antimicrobial activity. Regarding hygienic control, all gels with extracts were within the specified requirements in FA7. These results suggest the feasibility of using partially soluble in water extracts by employing hydrophilic excipients. These formulations would be a valid alternative for vehiculization of bioactive plant extracts considering that the bioactive compounds in gels retained the antimicrobial activity of extracts and they act as preservatives in gels.