Strips of all formulations of same size (7 × 5 mm) weighed on single pan balance and the average weight was calculated. This was repeated
for three sets of each film and the standard deviation was calculated. Periodontal films were left to swell for an hour on the surface of the agar plate, prepared by 2% agar medium under stirring and then pouring the solution in petridish to solidify at room temperature. The surface pH was measured by bringing a combined glass electrode by wrapping the strip around it and allowing to equilibrate for 1 min. Percentage Moisture Loss was determined by keeping the weighed strips in a desiccator containing anhydrous calcium chloride. After three days, the strips were taken out & re-weighed. The percentage moisture loss was calculated. Folding Endurance was evaluated Protein Tyrosine Kinase inhibitor by repeatedly folding a small strip of film of 2 × 2 cm size at the same place till it broke. The number of times, the strip was folded at the same place, without breaking, gave the value of folding endurance. The tensile strength of the films was determined by universal strength testing machine. The sensitivity of the machine is 1 g. It consists of
two load cell grips. The lower one is fixed and the upper one is movable. The test film of specific size was fixed between these cell grips and force was gradually applied till the film breaks. The tensile strength of the film was taken directly from the dial reading in kilograms. Content Uniformity was assessed by dissolving the drug loaded Raf kinase assay no strips of known weight (7 × 2 mm) in 10 ml of aqueous acetic acid, suitably diluted and the amount
of drug present was estimated by UV/VIS spectrophotometer (Shimadzu-UV 1700) at 286 nm. The stability of all the films was studied at different temperatures. The strips of size (7 × 2) were weighed in 3 sets. The strips were wrapped individually in aluminium foil and also in paper and placed in the petridishes. These were stored at ambient humid conditions, at room temperature (27 ± 2 °C), at 40 ± 2 °C and at refrigerator temperature (5–8 °C) for a period of 1 month. The samples were analysed for physical changes such as colour and texture. The drug content was estimated at an interval of 2 weeks. The solutions were further scanned to observe any possible spectral changes. In-vitro drug release was performed by taking films with drug in a vial containing 1 ml of pH 7.4 saline phosphate buffer. 1 ml of the solution was withdrawn from the vials and immediately replaced with 1 ml of fresh saline phosphate buffer. The drug content was estimated by measuring the absorbance after suitable dilutions in UV at λmax of 286 nm. In-vitro antibacterial activity was performed on all formulations by placing the film, cut into 0.7 × 0.5 sq.cm, on agar plates seeded with oral bacteria Staphylococcus aureus. After 48 h of incubation at 37 °c, the films were transferred onto freshly seeded agar plates for additional 48 h for incubation.