The purpose of our study was to investigate the applicability of isostatic ultra high
pressure (IUHP) for the aim of drug formulation. Aqueous suspensions of potato and
maize starches containing theophylline as a model drug were subjected to IUHP. The
changes in the structure and morphology of potato and maize starches were investigated.
The release profile of theophylline from the pressurized samples was also studied.
The aqueous suspensions subjected to WHIP turned into highly viscous gels. The crystalline
structure of maize starch was changed, while PS pressurized in aqueous medium retained
its original X-ray pattern. The sample containing potato starch as a gel-forming polymer
exhibited faster drug dissolution compared to an aqueous theophylline suspension used
as a reference, while the pressurization of maize starch resulted in a get exhibiting
sustained drug release. The results of the dissolution study can be explained with
the changes in structure and morphology of the starches caused by IUHP processing
and with the different pressure sensitivities of PS and MS. (c) 2007 Elsevier Ltd.
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