• Journal of Pharmaceutical Investigation
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• v.31 no.1
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• pp.19-25
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• 2001

The purpose of this study was to use a ternary polymeric matrix system for high drug loading of a highly soluble drug for controlled release delivery. The controlled drug delivery of diltiazem HCl (solubility > 50% in water at $25^{\circ}C$) with high loading dose (the final loading dose of drug was 34%) from a ternary polymeric matrix (gelatin, pectin, HPMC) was successfully accomplished. This simple monolithic system with 240 mg drug loading provided near zero-order release over a 24 hour-period by which time the system was completely dissolved. The release kinetics of diltiazem HCl tablet with high loading dose from the designed ternary polymeric system was dependent on the ratios of HPMC : pectin binary mixture. The release rate increased as pectin : HPMC ratio were increased. Swelling behavior of the ternary system and the ionic interaction of formulation components with cationic diltiazem molecule appear to control drug diffusion and the release kinetics. Comparable release profiles between commercial product and the designed system were obtained. The binding study between gelatin with diltiazem HCl showed the presence of two binding sites for drug interaction with subsequent controlled diffusion upon swelling. This designed delivery system is easy to manufacture and drug release behavior is highly reproducible and offers advantages over the existing commercial product.

• Journal of Pharmaceutical Investigation
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• v.31 no.1
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• pp.13-18
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• 2001

This study was to investigate the relationship between the gel layer thickness and swelling boundary via strength measurements using texture analysis. The novel texture analysis approach was used to examine the dynamics of swelling behavior in a ternary polymeric matrix tablet. The method permitted the characterization of the changes occurring at the peripheral as well as within interior boundary of the swelling during water ingress. The increase in gel strength for pectin, HPMC, and a ternary mixture with gelatin was found to depend on polymer concentration. Therefore, this method is further applicable to characterize the swelling behavior and provide opportunity to differentiate the gel-layer from that of swelling boundary.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.22-24
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• 1998

1. INTRODUCTION : The phase inversion method is widely used to prepare a variety of polymeric membranes ranging from micro-filtration to gas separation. The final morphology obtained by immersion precipitation strongly reflects the thermodynamics and kinetics of the system involved. The equilibrium thermodynamics of the ternary system of polymer/solvent/ nonsolvent is still very important to understand and predict membrane structure. Polysulfone (PSf) and polyethersulfone (PES) are important polymers as membrane materials due to the chemical resistance, mechanical strength, thermal stability and transport properies. There are several reports on the experimental phase diagrams in ternary mixtures of PSf/solvent/nonsolvent, and PES/solvent/nonsolvent. It would be interesting to investigate the solution thermodynamics containing these two polymers since PES is slightly less hyclrophobic than PSf.