Study on preparation of konjac glucomannan-hydroxypropyl methyl cellulose compression coated tablets for colonic delivery and in vitro release / 中国中药杂志

<p><b>OBJECTIVE</b>Prepare konjac glucomannan-hydroxypropyl methyl cellulose (HPMC) compression coated tablets and study the effects of the formulation, technics and in vitro dissolution condition on drug release behavior to elevate the colon-specific effects of preparation.</p><p><b>METHOD</b>Berberine hydrochloride core tablets were prepared by wet granulation technique and konjac glucomannan-HPMC mixture as the coating layer were used with compression coated technique. The effects of the formulation and technics on drug release behavior were investigated by dissolution test. The erosion of coat layer during dissolution test was investigated.</p><p><b>RESULT</b>Drug almost not released in dissolution medium stimulating gastric and intestinal condition, and released completely by coating layer erosion and rupture by enzyme in stimulating colonic condition. Drug release decreased with decreasing the ratio of konjac glucomannan-HPMC and increasing coat weight (P < 0.05), compression force was not found to be a significant factor on drug release. Drug release increased with increasing the concentration of beta-mannase in dissolution medium (P < 0.05), rotation speed has no effect on drug release. The release of drug was correlative with erosion of coat layer. The mechanism of drug release were diffusion and erosion.</p><p><b>CONCLUSION</b>The konjac glucomannan-HPMC compression coated tablets was a promising delivery system for drugs to be delivered to the colon.</p>

Identification of andrographolide hydroxypropyl-?-cyciodextrin inclusion compound and study on its thermodynamic stability / 中草药

Objective To prepare and identify the andrographolide-hydroxypropyl-?-cyclodextrin(an- drographolide-HP-?-CD)inclusion compound.The tool ratio between andrographolide and HP-?-CD and the thermodynamic constants in inclusion were studied simultaneously.Methods The andrographolide- HP-?-CD inclusion compound was prepared with lyophilization technique.Meanwhile,the inclusion com- pound was identified by differential scanning calorimetry(DSC)methods,infrared spectrometry(IR),and X-ray diffraction(XRD),respectively.The tool ratio between host and guest moleculars and the thermo- dynamic constants during the inclusion process were also researched by phase solubility method.Results An 1:1 molar ratio inclusion complex of andrographolide with HP-?-CD could be formed at 25,35,and 45 C.The phase diagram was A_L type and the procedure of inclusion was a heat release process.Conclusion The solubility of andrographolide-HP-?-CD inclusion compound can be increased obviously by the above- mentioned preparing techniques.