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Tablet shapes and in vitro evaluation of coated hydrophilic matrix tablets novel mupirocin formulations non-acidic enteric coating of omeprazole and novel hot-melt coating process

This dissertation is comprised of four distinct formulation sections, which
are described below:
A novel solid dosage formulation was investigated for achieving zero-order
drug release profile by combining tablet shape design and tablet membrane film
coating. Verapmail (model drug) was compressed into hydrophilic matrix tablet
cores of flat-faced and bi-convex shape, which were encapsulated with membrane
controlling film. The hydrophilic tablet core contained hydroxypropyl
methylcellulose (HPMC) 15 LV, pectin, and Avecil��. The membrane film coating
solution was comprised of deionized water, Opadry��, Surelease�� and talc. The
combination of membrane film coating and tablet shape design was found to
influence in vitro verapamil release profile towards the zero-order release
demonstrated by the commercial Covera HS�� (Pharmacia).
An alternative formulation for the commercial Bactroban�� (Smithkline
Beacham) ointment 2% was developed. Both the texture and consistency of the
new ointment were comparable to the Bactroban�� ointment. The new and the
commercial formulations were found to be equivalent in drug release by the Bauer-Kirby test. Mupirocin remained unstable in the new formulation. Mg����� was added
to help stabilize mupirocin and was shown to complex with mupirocin by nuclear
magnetic resonance (NMR). The modified formulation including Mg����� however
failed to stabilize mupirocin. The stability assay results showed an average of
67.2% mupirocin recovery along with 25.2% degradation products.
A generic omeprazole formulation was developed, which was comprised of
nonpareil core, omeprazole matrix layer, and an enteric locating layer of
ammoniated hydroxypropyl methylcellulose phthalate (HPMCP) 55S. The new
formulation was gastro-resistant in protecting against omeprazole degradation for
up to 2 h, but failed to dissolve as rapidly as the commercial Prilosec�� (Astra
Merk) in simulated intestinal fluid. The addition of expotab�� to the enteric coating
layer failed to improve omeprazole dissolution rate.
A novel hot-melt coating methodology utilizing direct blending technique
has been developed. The processing steps for the direct blending hot-melt coating
are: (a) Hot-melt system preparation; (b) Dispersion/dissolution of the active
ingredient(s) in the hot-melt system; (c) Pre-heating of the coating substrate; and
(d) Cooling and congealing of the hot-melt on substrate surface. Immunogenic
effect was observed in mice administered with enteric-coated ragweed pollen
extract (RPE) alpha fraction by the hot-melt coating encapsulation with direct
blending method. The effect was not shown to be statistically significant. / Graduation date: 2003

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/31105
Date14 May 2002
CreatorsLeung, Manshiu
ContributorsAyres, James W.
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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