Physiological and Pharmaceutical Considerations for Rectal Drug Formulations.

Area of Science:

• Pharmacology and Pharmaceutics
• Gastroenterology

Background:

• Oral drug administration is preferred but not always feasible due to clinical or pharmaceutical limitations.
• Rectal drug delivery serves as a practical alternative for both local and systemic therapeutic actions.
• The rectal environment offers stability, low enzymatic activity, and partial avoidance of hepatic first-pass metabolism.

Purpose of the Study:

• To review physiological and pharmaceutical factors influencing rectal drug delivery.
• To discuss conventional and novel rectal drug delivery systems.
• To explore translational challenges and development of new rectal formulations.

Main Methods:

• Literature review of physiological and pharmaceutical considerations for rectal drug delivery.
• Analysis of conventional and novel drug delivery approaches.
• Discussion of formulation optimization, bioavailability, retention, and release kinetics.

Main Results:

• Rectal delivery can achieve significant local and systemic drug levels.
• Formulation advancements have improved bioavailability, retention, and release kinetics.
• Despite progress, clinical translation of rectal drug delivery systems remains limited.

Conclusions:

• Rectal drug delivery is a promising alternative route with unique physiological advantages.
• Ongoing pharmaceutical development enhances rectal formulation performance.
• Overcoming translational challenges is crucial for wider clinical adoption of novel rectal delivery systems.