Achievements in Thermosensitive Gelling Systems for Rectal Administration

Abstract

Rectal drug delivery is an effective alternative to oral and parenteral treatments. This route allows for both local and systemic drug therapy. Traditional rectal dosage formulations have historically been used for localised treatments, including laxatives, hemorrhoid therapy and antipyretics. However, this form of drug dosage often feels alien and uncomfortable to a patient, encouraging refusal. The limitations of conventional solid suppositories can be overcome by creating a thermosensitive liquid suppository. Unfortunately, there are currently only a few studies describing their use in therapy. However, recent trends indicate an increase in the development of this modern therapeutic system. This review introduces a novel rectal drug delivery system with the goal of summarising recent developments in thermosensitive liquid suppositories for analgesic, anticancer, antiemetic, antihypertensive, psychiatric, antiallergic, anaesthetic, antimalarial drugs and insulin. The report also presents the impact of various types of components and their concentration on the properties of this rectal dosage form. Further research into such formulations is certainly needed in order to meet the high demand for modern, efficient rectal gelling systems. Continued research and development in this field would undoubtedly further reveal the hidden potential of rectal drug delivery systems.

Keywords: drug delivery system; poloxamer; rectal drug delivery; rectal gel; solid suppository; thermosensitive gel; thermosensitive liquid suppository.

Figure 1

Venous and lymphatic drainage from the rectum.

Figure 2

The chemical structure of exemplary polymers used in the production of thermosensitive liquid suppository: (a) poloxamer, (b) polivinylpyrrolidone, (c) methylcellulose, (d) sodium alginate, (e) polyacrylic acid.