Jing Li

Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Pharmaceutical Sciences


Gellan gum is an anionic polysaccharide produced by the aerobic fermentation of Pseudomonas elodea in batch culture. It consists of P-D-glucuronic acid, P-D-glucose and a-L-rhamnose monosaccharide in molar ratios of 1 :2: 1. Gellan undergoes calciuminduced crosslinking to form a three dimensional network and this property makes it particularly attractive for the incorporation of biological moieties such as proteins. In this study, the procedure for the preparation of gellan films was developed, optimized and the characteristics of these films were investigated. In addition, the effects of the concentration of each ingredient in gellan films and molecular weights of fluorescein isothiocyanate dextran (FD) on the release behavior of FD from these films were examined. FD-40 (MW=40,000) release can be prolonged with increases in concentrations of gellan and CaC12• As the molecular weight of FD increased, its release rate from the films decreased. The addition of polyvinyl alcohol (PV A) to gellan films sustained the release of FD-40 for more than 6 days. While increases in gellan and CaC12 concentrations did not significantly affect FD-40 release from the PVA containing films, their addition eliminated the phenomenon of film curling. This film device was implanted for insulin delivery in rats. The film slabs were implanted intraperitoneally in the lower abdomen of the rats and insulin release was evaluated by assessing its hypoglycemic effect in diabetic rats. The glucose levels of the diabetic rats implanted with insulin-loaded films were about half of those implanted with blank films, and this therapeutic effect of insulin could last for one week. Both in vitro and in vivo studies indicated that the gellan film could be an ideal candidate in the development of protein delivery systems.

Library of Congress Subject Headings

Drug delivery devices


Protein drugs



Number of Pages



South Dakota State University