Application of pectin in oral drug delivery.

INTRODUCTION: Biopolymers have been used extensively in the pharmaceutical field. Pectin, a biopolymer, has several unique properties that enable it to be used as an excipient or carrier for oral drug delivery systems. Accordingly, several investigators have identified the benefits of pectin-based delivery systems for oral drug administration. AREAS COVERED: This review first describes the chemical structure, source and production, degree of esterification and gel formation properties of pectin. The application of pectin in various oral drug delivery platforms is also discussed, that is, controlled release systems, gastro-retentive systems, colon-specific delivery systems and mucoadhesive delivery systems. EXPERT OPINION: Pectin from different sources provides different gelling abilities, due to variations in molecular size and chemical composition. Like other natural polymers, a major problem with pectin is inconsistency in reproducibility between samples, which may result in poor reproducibility in delivery characteristics. Scintigraphic studies and in vivo studies, in both animals and human volunteers, demonstrate the successful development of a pectin-based colon-specific drug delivery system. Pectin-based controlled release systems, gastro-retentive systems and mucoadhesive systems present promising approaches for increasing the bioavailability of drugs, but are in their infancy. A lack of direct correlation between in vitro release and in vivo absorption studies is a major concern with these systems.