Microparticles as controlled drug delivery carrier for the treatment of ulcerative colitis: A brief review

Abstract

Ulcerative colitis is the chronic relapsing multifactorial gastrointestinal inflammatory bowel disease, which is characterized by bloody or mucus diarrhea, tenesmus, bowel dystension, anemia. The annual incidence of ulcerative colitis in Asia, North America and Europe was found to be 6.3, 19.2 and 24.3 per 100,000 person-years. The major challenge in the treatment of ulcerative colitis is appropriate local targeting and drug related side-effects. To overcome these challenges, microparticulate systems seem to be a promising approach for controlled and sustained drug release after oral administration. The main goal of this article is to explore the role of microparticles in ulcerative colitis for the appropriate targeting of drugs to colon. There are different approaches which have been studied over the last decade, including prodrugs, polymeric approach, time released system, pH sensitive system, which show the site specific drug delivery to colon. Among these approaches, microparticulate drug delivery system has been gaining an immense importance for local targeting of drug to colon at a controlled and sustained rate. Combined approaches such as pH dependent and time dependent system provide the maximum release of drug into colon via oral route. This article embraces briefly about pathophysiology, challenges and polymeric approaches mainly multiparticulate systems for site specific drug delivery to colon in sustained and controlled manner so that drug related side-effects by reducing dosage frequency can be minimized.

Keywords: Colon; Inflammatory bowel disease; Multiparticulate carrier; Ulcerative colitis; pH sensitive polymer.

Figure 1

A schematic diagram for ulcerative colitis.

Figure 2

Diagrammatic scheme of pathogenesis of inflammatory bowel disease by following pathway of T-Lymphocyte activation.

Figure 3

(1) Uninflammed mucosa: (a) Particle size <500 nm shows endocytotic uptake, (b) particle size <5 nm shows lymphatic uptake. (2) Inflammed mucosa: Increased particle uptake due to leaky epithelium.

Figure 4

Mechanism of drug release through controlling membrane.

Figure 5

Mechanism of drug release through polymer matrix.