Journal
EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS
Volume 53, Issue 1, Pages 87-98Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S0939-6411(01)00205-3
Keywords
guar gum; graft copolymer; microsphere; water transport; drug release
Categories
Ask authors/readers for more resources
The graft copolymer (pAAm-g-GG) of guar gum with acrylamide was prepared and cross-linked with glutaraldehyde to form the hydrogel microspheres by the water-in-oil (w/o) emulsification method. The microspheres were loaded with two antihypertensive drugs, verapamil hydrochloride (water-soluble) and nifedipine (water-insoluble) to investigate their controlled release characteristics. The drugs were incorporated either during cross-linking by dissolving it in the reaction medium or after cross-linking by the soaking technique. The microspheres were characterized by Fourier transform infrared spectroscopy, thermogravimetry, differential scanning calorimetry, equilibrium water uptake and dynamic swelling. The microspheres are spherical with smooth surfaces. Dynamic swelling experiments indicated that with an increase in cross-linking, water transport deviates from Fickian to non-Fickian mechanism. The in vitro drug release showed a dependence on the extent of cross-linking, amount of drug loading, nature of drug molecule and method of drug loading. Even though the release of drugs is swelling controlled in the initial stages, in the later stage diffusion of the solute is dominating. Various transport parameters have been calculated and the results are discussed in terms of the nature of the drug and the polymer. (C) 2002 Elsevier Science B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available