Biochemical and Mechanical Characterization of Enzyme-Digestible Hydrogels
- 1 January 1990
- journal article
- Published by Springer Science and Business Media LLC in Pharmaceutical Research
- Vol. 07 (8), 816-823
- https://doi.org/10.1023/a:1015956714669
Abstract
Albumin-cross-linked hydrogels were prepared by free radical polymerization using 1-vinyl-2-pyrrolidinone as a monomer and functionalized albumin as a crosslinking agent. The degree of chemical cross-linking was controlled by varying the degree of albumin functionality and the concentration of albumin. With emphasis placed on the potential use of these hydrogels for long-term oral drug delivery, gel characterization studies examined both the swelling and the mechanical properties in the absence and presence of pepsin. In the absence of pepsin, the equilibrium swelling ratio in simulated gastric fluid ranged from 17 to 55, depending on the degree of albumin functionality and the albumin concentration. Swelling was pH dependent at pH's greater than 7. The uptake of solvent into the dried hydrogels was determined to be Fickian. The integrity of swelling gels was dependent on the concentration of the functionalized albumin as well as on the degree of albumin functionality. In the presence of pepsin, a predominance of either surface or bulk degradation was observed, depending on the functionality of the albumin used as a cross-linker. Gel integrity during pepsin degradation also showed a marked dependence on the albumin functionality.Keywords
This publication has 16 references indexed in Scilit:
- Gastric emptying of large single unit dosage formsJournal of Pharmacy and Pharmacology, 1988
- The effect of density on the gastric emptying of single- and multiple-unit dosage forms.Pharmaceutical Research, 1986
- Bioadhesive Polymers as Platforms for Oral Controlled Drug Delivery II: Synthesis and Evaluation of Some Swelling, Water-Insoluble Bioadhesive PolymersJournal of Pharmaceutical Sciences, 1985
- The Physiology and Pathophysiology of Gastric Emptying in HumansGastroenterology, 1984
- Gastric emptying of enteric-coated tabletsDigestive Diseases and Sciences, 1984
- The principles of enzyme stabilization IV. Modification of ‘key’ functional groups in the tertiary structure of proteinsBiochimica et Biophysica Acta (BBA) - Enzymology, 1979
- Distribution of pellets in the gastrointestinal tract. The influence on transit time exerted by the density or diameter of pelletsJournal of Pharmacy and Pharmacology, 1978
- Measurement of Gastric Functions During Digestion of Ordinary Solid Meals in ManGastroenterology, 1976
- Investigation of small bowel transit time in man utilizing pulmonary hydrogen (H2) measurements.1975
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970