Formulation and Characterization of Diazepam Thermosensitive Rectal Gel: Investigating the Role of Mucoadhesive Polymers

Background: The study developed a rectal in-situ gel of diazepam using thermosensitive polymer poloxamer 407 (P407). The newer form of in-situ rectal diazepam gel holds great promise in terms of effectiveness and ease of use. This in-situ gel is a remarkable combination of two phar-maceutical forms: a solution and a gel. Objective: The study aims to formulate a rectal in-situ gel of diazepam to improve rectal residence time for treating insomnia, convulsions, and status epilepticus. This innovative approach holds great potential for future application and the study of the effect of the addition of HPMC into the formula-tion. Method: Ten formulations with varying concentrations of P407 (14%-19%) and HPMC (0.25%-1%) were prepared and assessed for gelation temperature and time, mucoadhesive force, in-vitro drug release, and FTIR compatibility. Results: The optimized formula, F5 (18% P407), demonstrated a gelation temperature of 37±3.775?, gelation time of 341 seconds, mucoadhesive force of 4021 dyne/cm², 100% in-vitro drug release within 8 hours, and 65.23% ex-vivo permeation in 12 hours. Conclusion: The study concluded that diazepam can be effectively formulated as a thermosensitive in-situ gel for rectal administration. However, the addition of HPMC negatively impacts the physico-chemical properties of the gel.