Optimisation of topical antibacterial preparation from Malaysian kelulut honey by using xanthan gum as polymeric agent

@#The study aims to formulate and optimise topical antibacterial preparation by using Malaysian kelulut honey as the active ingredient and xanthan gum as the polymeric agent. Response surface methodology was used to optimise the preparation. The acidity, honey concentration and xanthan gum concentration were the independent variables. The zone of inhibitions on S. aureus ATCC6538 and E. coli ATCC8739 were the response variables. The optimal preparation was evaluated on its physicochemical properties, viscosity, antibacterial efficacy and stability. The antibacterial efficacy of the optimal preparation was compared to the commercially antibacterial gel (MediHoney™, Comvita). The optimal preparation was formulated at pH of 3.5, honey concentration of 90% (w/v) and xanthan gum concentration of 1.5% (w/v) with the inhibition zones measured on S. aureus ATCC6538 was 16.2 mm and E. coli ATCC8739 was 15.8 mm respectively. The factors of acidity and honey concentration have significantly influenced the inhibition zone on S. aureus ATCC6538 and E. coli ATCC8739. The utilisation of xanthan gum as the polymeric agent was fit for the preparation which showed by adequate physicochemical properties and retained of the antibacterial effects. This was supported by constant viscosity and efficacy of the preparation within the six months of stability study indicating stable and reliable preparation. Xanthan gum is a potential polymeric agent due to its effective use in preparing stable preparation with effective antibacterial properties.

Insecticide susceptibility status of Anopheles koliensis (Diptera: Culicidae) in northeastern Irian Jaya, Indonesia.

Anopheles koliensis, an important malaria vector in the interior region of Irian Jaya, Indonesia, was evaluated for susceptibility to three different insecticide compounds using the standard World Health Organization diagnostic test kit and pretreated impregnated papers. A series of tests were conducted in Arso PIR I, a transmigrant settlement 60 km south of Jayapura, from January 1988 to May 1989. All compounds were tested at the recommended diagnostic dosage and exposure time. An. koliensis were susceptible to 1.0% fenitrothion at two hour exposure (N = 358) and 5.0% malathion at one hour exposure (N = 371) after the 24-hour holding period. Significant resistance to DDT was observed in both the An. koliensis and Culex quinquefasciatus populations. Approximately 30% of the An. koliensis population (N = 468) was resistant to 4% DDT at both one and two hour exposures. These findings indicate that routine use of DDT in Arso PIR I for indoor residual house spraying may be of limited effectiveness, in part, because of physiological resistance. However, use of an alternative insecticide will be more expensive and might prove equally ineffective because of the exophilic behavior of the species. This is the first confirmed report from repeated observations of DDT resistance in An. koliensis from Indonesia.