Thermo-activated in situ rectal gel preparation for Ibuprofen using eutectic mixture.

This study aimed to develop a thermosensitive in situ gel formulation for rectal delivery of Ibuprofen as an efficient alternative dosage form. Utilizing poloxamer 188, poloxamer 407, and HPMC via cold technique method, a thermosensitive in situ gel was successfully prepared. The concentration of Ibuprofen in the formulations was 1.2 % (w/w). The prepared gels underwent assessment for clarity, gelation temperature, gelation time, gel strength, spread ability, syringe-ability, pH, viscosity, FTIR, and drug content. The selected formulations exhibited a gelation temperature within the range of 30 °C to 36 °C, with consistent amount of drug soluble in the formulations (93 % - 110 %). Mucoadhesive studies, in vitro release tests, ex vivo modeling of drug release, kinetic studies modeling, and histopathology testing were also conducted. The formulation comprising 18 % poloxamer 407, 12 % poloxamer 188, and 1 % sodium chloride (FS15) demonstrated suitable gelation temperature and desirable drug release rate. In vitro drug release tests indicated completion within one hour for both FS10 (20 % P407 & 10 % P188) and FS15 (18 % P407 & 12 % P188), with consistent and predictable release patterns observed through kinetic modeling analysis. Microscopic histopathology examination confirmed the safety of the selected formula, exhibiting no irritation in the mucosal membrane of the sheep. In conclusion, Ibuprofen thermosensitive in situ gel presents a promising and convenient strategy as a rectal carrier and an alternative dosage form to solid suppositories.