Recent advances in oral in situ gel drug delivery system: a polymeric approach.

Abstract

Objectives: This review aims to explore in situ gelling drug delivery systems with emphasis on formulation strategies, gelation mechanisms, administration routes, and therapeutic benefits. It also seeks to understand the role of different polymers in achieving optimal gelation and drug release profiles. Additionally, the review aims to identify current research gaps and highlight potential areas for future development and clinical translation.

Significance: In situ gels are liquid formulations that convert into gels upon exposure to physiological triggers such as pH, temperature, or ionic strength. These systems offer advantages like sustained drug release, improved bioavailability, and enhanced patient compliance. Their adaptability supports various administration routes including ocular, nasal, oral, gastrointestinal, vaginal, and bladder delivery.

Key findings: A wide range of natural, synthetic, and semi-synthetic polymers have been studied for their in situ gelation properties. Most formulations exhibit rapid gelation upon contact with biological fluids and demonstrate good physicochemical stability. Controlled and sustained drug release was observed in vitro across different polymeric systems. The inclusion of mucoadhesive agents significantly improved residence time at the site of administration and enhanced drug absorption. These systems were found to be compatible with multiple delivery routes and maintained stability under physiological conditions.

Conclusion: In situ gelling drug delivery systems represent a versatile and efficient approach for site-specific, controlled drug release. Their ability to respond to physiological stimuli and improve mucosal retention makes them a promising alternative to traditional formulations. Continued research into polymer optimization and clinical application may further expand their therapeutic potential.