Properties of bioadhesive ketoprofen liquid suppositories: preparation, determination of gelation temperature, viscosity studies and evaluation of mechanical properties using texture analyzer by 4 x 4 factorial design

Context: Development and evaluation of thermosensitive and bioadhesive liquid suppositories containing ketoprofen (KP). Objective: This study was conducted to develope thermosensitive and bioadhesive liquid suppositories containing KP using poloxamer and different bioadhesive polymers and to investigate their gelation temperature, viscosity and mechanical properties. Materials and methods: Bioadhesive liquid suppositories were prepared by the cold method using poloxamer 407 (P 407), Poloxamer 188 (P 188) and various amounts of different bioadhesive polymers. Their gelation temperatures, viscosity values and mechanical properties were determined using texture analyzer by 4 x 4 factorial design. Results: It was seen that in presence of KP, gelation temperature of formulation P 407/P 188 (4/20%) significantly decreased from 64 to 37.1 degrees C. It is to be noted that addition of increasing concentrations of bioadhesive polymers lowered gelation temperature and its decrease was highest with addition of Carbopol 934 P (C). Results of texture profile analysis (TPA) showed that formulations containing C have significantly higher hardness and adhesiveness values than other bioadhesive formulations. According to TPA, gel structure of liquid suppository formulation F5, containing P 407/P 188/KP/C (4/20/2.5/0.8%), exhibited the greatest hardness, compressibilty, adhesiveness and besides greatest viscosity. Discussion and conclusion: According to mechanical properties and viscosity values, it was concluded that F5 could be a promising formulation.