Chitosan (1.4%w/v) in 1%w/v lactic acid or 2%w/v acetic acid solutions was prepared by stirring overnight using magnetic stirrer. The resulting solution was filtered through a sintered glass filter to remove the extraneous matter, followed by casting on glass plate and dried in an oven (Memmert, Germany) at 60°C for 24 hours. After drying, the transparent film was carefully peeled off from the glass plate. The films were stored in an air tight glass container maintained at room temperature of 25 ± 1°C and relative humidity of 60-65% until further investigations. The thickness of the film sample was measured using a micrometer (Digimatic Micrometer, Mitutoyo, Tokyo, Japan) at five locations (center and four corners), and the mean thickness calculated. Samples with air bubbles, nicks or tears and having mean thickness variations of greater than 5% were excluded from analysis.