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Colon specific chitosan microspheres for chronotherapy of chronic stable angina.
Colloids Surf B Biointerfaces. 2011 Apr 01; 83(2):277-83.CS

Abstract

In the present work, chitosan microspheres with a mean diameter between 6.32 μm and 9.44 μm, were produced by emulsion cross-linking of chitosan, and tested for chronotherapy of chronic stable angina. Aiming at developing a suitable colon specific strategy, diltiazem hydrochloride (DTZ) was encapsulated in the microspheres, following Eudragit S-100 coating by solvent evaporation technique, exploiting the advantages of microbiological properties of chitosan and pH dependent solubility of Eudragit S-100. Different microsphere formulations were prepared varying the ratio DTZ:chitosan (1:2 to 1:10), stirring speed (1000-2000 rpm), and the concentration of emulsifier Span 80 (0.5-1.5% (w/v)). The effect of these variables on the particle size and encapsulation parameters (production yield (PY), loading capacity (LC), encapsulation efficiency (EE)) was evaluated to develop an optimized formulation. In vitro release study of non-coated chitosan microspheres in simulated gastrointestinal (GI) fluid exhibited a burst release pattern in the first hour, whereas Eudragit S-100 coating allowed producing systems of controlled release diffusion fitting to the Higuchi model, and thus suitable for colon-specific drug delivery. DSC analysis indicated that DTZ was dispersed within the microspheres matrix. Scanning electron microscopy revealed that the microspheres were spherical and had a smooth surface. Chitosan biodegradability was proven by the enhanced release rate of DTZ in presence of rat caecal contents.

Authors+Show Affiliations

Department of Pharmaceutical Sciences, Mahatma Gandhi University, Cheruvandoor Campus, Ettumanoor-686 631, Kerala, India.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

21194900

Citation

Jose, S, et al. "Colon Specific Chitosan Microspheres for Chronotherapy of Chronic Stable Angina." Colloids and Surfaces. B, Biointerfaces, vol. 83, no. 2, 2011, pp. 277-83.
Jose S, Prema MT, Chacko AJ, et al. Colon specific chitosan microspheres for chronotherapy of chronic stable angina. Colloids Surf B Biointerfaces. 2011;83(2):277-83.
Jose, S., Prema, M. T., Chacko, A. J., Thomas, A. C., & Souto, E. B. (2011). Colon specific chitosan microspheres for chronotherapy of chronic stable angina. Colloids and Surfaces. B, Biointerfaces, 83(2), 277-83. https://doi.org/10.1016/j.colsurfb.2010.11.033
Jose S, et al. Colon Specific Chitosan Microspheres for Chronotherapy of Chronic Stable Angina. Colloids Surf B Biointerfaces. 2011 Apr 1;83(2):277-83. PubMed PMID: 21194900.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Colon specific chitosan microspheres for chronotherapy of chronic stable angina. AU - Jose,S, AU - Prema,M T, AU - Chacko,A J, AU - Thomas,A Cinu, AU - Souto,E B, Y1 - 2010/12/01/ PY - 2010/09/17/received PY - 2010/11/23/revised PY - 2010/11/23/accepted PY - 2011/1/4/entrez PY - 2011/1/5/pubmed PY - 2011/4/26/medline SP - 277 EP - 83 JF - Colloids and surfaces. B, Biointerfaces JO - Colloids Surf B Biointerfaces VL - 83 IS - 2 N2 - In the present work, chitosan microspheres with a mean diameter between 6.32 μm and 9.44 μm, were produced by emulsion cross-linking of chitosan, and tested for chronotherapy of chronic stable angina. Aiming at developing a suitable colon specific strategy, diltiazem hydrochloride (DTZ) was encapsulated in the microspheres, following Eudragit S-100 coating by solvent evaporation technique, exploiting the advantages of microbiological properties of chitosan and pH dependent solubility of Eudragit S-100. Different microsphere formulations were prepared varying the ratio DTZ:chitosan (1:2 to 1:10), stirring speed (1000-2000 rpm), and the concentration of emulsifier Span 80 (0.5-1.5% (w/v)). The effect of these variables on the particle size and encapsulation parameters (production yield (PY), loading capacity (LC), encapsulation efficiency (EE)) was evaluated to develop an optimized formulation. In vitro release study of non-coated chitosan microspheres in simulated gastrointestinal (GI) fluid exhibited a burst release pattern in the first hour, whereas Eudragit S-100 coating allowed producing systems of controlled release diffusion fitting to the Higuchi model, and thus suitable for colon-specific drug delivery. DSC analysis indicated that DTZ was dispersed within the microspheres matrix. Scanning electron microscopy revealed that the microspheres were spherical and had a smooth surface. Chitosan biodegradability was proven by the enhanced release rate of DTZ in presence of rat caecal contents. SN - 1873-4367 UR - https://www.unboundmedicine.com/medline/citation/21194900/Colon_specific_chitosan_microspheres_for_chronotherapy_of_chronic_stable_angina_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0927-7765(10)00664-8 DB - PRIME DP - Unbound Medicine ER -