Antibacterial assay of crosslinked PVA SA xerogel membranes
15 ml of FC reagent was added into a series of 50 ml conical flasks containing sodium ampicillin (0.2–0.8 mg). Sodium ampicillin was chosen as a topical long acting antibiotic which also has good water solubility in an aqueous solution and it has broad-spectrum antibiotic which means that it kills more kinds of bacteria than other SR3335 family and gentamicin antibiotics. Sodium ampicillin was utilized as an antibiotic instead of gentamicin sulfate salt which is loaded with PVA-dextran membranes and was discussed elsewhere (Hwang et al., 2010). The contents were completely mixed and kept into a ray-finned thermostated water bath at 95 °C for 30 min. The flasks were taken out cooled at room temperature at ∼25 °C, then transferred into a 25 ml standard volumetric flask and diluted up to the mark with distilled water. The absorbance of the resulting blue color of dye was measured against a blank reagent at 750 nm using spectrophotometer as previously discussed (Queiroz et al., 2001, Lin et al., 2006 and Ahmad et al., 2004).