The organoleptic properties (color, odor), pH, drug content and release profiles of the gels stored at 20��C were examined after the following time periods (0 h, 24 h, 6 months). Studies of equilibrium swelling in the alternative drug delivery inhibitor Palbociclib systems Known weights of nystatin-containing dry gels were immersed in pH 4.0 and pH 9.0 buffer solutions, respectively and kept at 25��C for 48 h until equilibrium of swelling had been reached. The swollen gels were removed, the excess of water on the surfaces absorbed with a filter paper and the gels immediately weighed on a microbalance. The equilibrium-swelling ratio (SR) was calculated using the following equation: SR=(Ws?Wd)/Wd �� 100% Where Ws and Wd are the weights of the gels at equilibrium swelling state and at dry state, respectively.

[23] Experiments were repeated in triplicate for each gel specimen, and the mean value was obtained. In vitro study of nystatin release profile The release study was carried out with United States Pharmacopeia (USP) dissolution apparatus type 1 (Copley UK), slightly modified in order to overcome the small volume of the dissolution medium by using 100 ml beakers instead of the jars. The basket of the dissolution apparatus (2.5 cm in diameter) was filled with 1 g of nystatin gel on filter paper. The basket was immersed to about 1 cm of its surface in 50 ml of phosphate buffer pH 6.8, at 37��C �� 0.5 and at 100 rpm.[24] Samples (2 ml) were collected at 0.25, 1, 2, 3, 4, 5, 6, 7 and 8 h[25] and were analyzed by a ultraviolet-visible spectrophotometer (Cintra 5, GBC Scientific Equipment, Australia) at a wavelength (��) of max 306 nm.

[26] Each sample was replaced by the same volume of phosphate buffer at a pH of 6.8 to maintain its constant volume and sink condition.[27] Shear bond strength tests for dentine bonding Extracted human molars were used within 2 months of storage in water containing thymol crystals. Only undamaged teeth were selected. The roots of the teeth were removed and all the occlusal enamel ground away (at a 90�� angle by using a jig) to expose the underlying dentin. The teeth were embedded in 10 mm length PVC (Consjit Tubing, SA PVC, JHB, RSA) pipes with cold cure acrylic resin so that the grounded dentin projected well above the acrylic and the dentin then thoroughly washed under tap water. Two composite studs (SDR, Dentsply, New York, USA, Batch No.

1105000609), each with an internal diameter of 2.5 mm and height of 3 mm, were bonded to the polished dentine surface (up to 600-grit fineness) of each tooth via a bonding agent, XP bond (Dentsply, Carfilzomib New York, USA) as suggested by the manufacturer. The bonding agent contained: Carboxylic acid modified dimethacrylate (tetracarboxylic acid resin), phosphoric acid modified acrylate resin, urethane dimethacrylate, triethyleneglycol dimethacrylate, 2-hydroxyethylmethacrylate, butylated benzenediol (stabilizer), ethyl-4-dimethylaminobenzoate, camphorquinone, functionalized amorphous silica and t-butanol.