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

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Rectal drug delivery offers an alternative route for systemic administration.
• Conventional suppositories can be inconvenient and have variable absorption.
• In situ forming gels provide localized and sustained drug release.

Purpose of the Study:

• To develop and characterize a thermosensitive in situ gel for rectal delivery of Ibuprofen.
• To evaluate the formulation's physicochemical properties, drug release, and safety profile.
• To establish Ibuprofen in situ gel as a viable alternative to traditional rectal dosage forms.

Main Methods:

• Thermosensitive in situ gels were prepared using poloxamer 188, poloxamer 407, and HPMC via the cold technique.
• Formulations were evaluated for gelation temperature, time, strength, spreadability, syringeability, pH, viscosity, and drug content.
• In vitro drug release, mucoadhesion, ex vivo modeling, kinetic analysis, and histopathology were performed.

Main Results:

• Optimized formulations exhibited gelation temperatures between 30-36°C and drug content of 93-110%.
• Selected formulations (FS10, FS15) achieved complete in vitro drug release within one hour with predictable kinetics.
• Histopathology confirmed the absence of mucosal irritation in sheep models.

Conclusions:

• Thermosensitive Ibuprofen in situ gel is a promising rectal carrier.
• This formulation offers a convenient and effective alternative to solid suppositories.
• The developed in situ gel demonstrates good physicochemical properties, rapid drug release, and excellent safety for rectal administration.