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HERO ID
2345935
Reference Type
Journal Article
Title
Accelerating the dissolution of enteric coatings in the upper small intestine: evolution of a novel pH 5.6 bicarbonate buffer system to assess drug release
Author(s)
Varum, FJ; Merchant, HA; Goyanes, A; Assi, P; Zboranová, V; Basit, AW
Year
2014
Is Peer Reviewed?
Yes
Journal
International Journal of Pharmaceutics
ISSN:
0378-5173
EISSN:
1873-3476
Volume
468
Issue
1-2
Page Numbers
172-177
Language
English
PMID
24727141
DOI
10.1016/j.ijpharm.2014.04.019
Web of Science Id
WOS:000336486600020
Abstract
Despite rapid dissolution in compendial phosphate buffers, gastro resistant (enteric coated) products can take up to 2 h to disintegrate in the human small intestine, which clearly highlights the inadequacy of the in vitro test method to predict in vivo behaviour of these formulations. The aim of this study was to establish the utility of a novel pH 5.6 bicarbonate buffer, stabilized by an Auto pH™ System, as a better surrogate of the conditions of the proximal small intestine to investigate the dissolution behaviour of standard and accelerated release enteric double coating formulations. Prednisolone tablets were coated with 3 or 5 mg/cm(2) of partially neutralized EUDRAGIT(®) L 30 D-55, HP-55 or HPMC adjusted to pH 6 or 8. An outer layer of EUDRAGIT(®) L 30 D-55 was applied at 5mg/cm(2). For comparison purposes, a standard single layer of EUDRAGIT(®) L 30 D-55 was applied to the tablets. Dissolution was carried out using USP II apparatus in 0.1 M HCl for 2 h, followed by pH 5.6 bicarbonate buffer. EUDRAGIT(®) L 30 D-55 single-coated tablets showed a slow drug release with a lag time of 75 min in buffer, whereas release from the EUDRAGIT(®) L 30 D-55 double-coated tablets was accelerated. These in vitro lag times closely match the in vivo disintegration times for these coated tablets reported previously. Drug release was further accelerated from modified double coatings, particularly in the case of coatings with a thinner inner layer of HP-55 or HPMC (pH 8 and KH2PO4). This study confirms that the pH 5.6 bicarbonate buffer system offers significant advantages during the development of dosage forms designed to release the drug in the upper small intestine.
Keywords
Gastro resistant coatings; Bicarbonate buffers; Biorelevant dissolution; pH responsive polymers; Hypromellose phthalate; Enteric polymers
Tags
IRIS
•
Phthalates – Targeted Search for Epidemiological Studies
Source – all searches
Pubmed
WOS
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Source - Jun 2014 Update (Private)
Pubmed
WOS
Source – Dec 2014 Update (Private)
WOS
Source – Mar 2015 Update (Private)
Pubmed
WOS
Source – Dec 2015 Update (Private)
Pubmed
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