Effects of three aqueous extraction preprocessing methods on total coumarins extract of Angelicae dahuricae Radix / 中成药

AIM To investigate the effects of aqueous extraction at normal temperature,40 ℃,and water boiling on total coumarins extract of Angelicae dahuricae Radix.METHODS For the extracts Ⅰ-Ⅳ obtained by ethanol reflux extraction and three aqueous extraction preprocessing methods,respectively,UV and HPLC were adopted in the content determination of total coumarins and imperatorin,then the powder properties and dissolution rates were compared.RESULTS The contents of total coumarins in four extracts were 3.98％,6.03％,6.81％ and 4.46％,while those of imperatorin were 0.633％,0.540％,0.465％ and 0.155％,respectively.The angles of repose were 48.455°,42.587°,42.689° and 42.024° with the bulk densities of 0.214,0.324,0.316 and 0.354 g/cm3,respectively.Within 100 min,extract Ⅰ demonstrated higher moisture adsorption rate and equilibrium moisture absorption content than the other three extracts.The accumulative dissolution rates of various extracts were much higher than that of medicinal material fine powder within 120 min.CONCLUSION All the three aqueous extraction preprocessing methods can obviously improve the powder properties of total coumarins extract of A.dahuricae Radix and increase the dissolution rate of medicinal material fine powder.

Preparation of silymarin solid dispersions and dissolution rates of five constituents / 中成药

AIM To prepare silymarin solid dispersions and to evaluate the dissolution rates of five constituents.METHODS Taking F68 and PVPk30 as a combined carrier,the solid dispersions were prepared by solvent fusion method.Then the effects of combined carrier ratio and drug-carrier ratio on dissolution rates of silybin,isosilybin,silydianin,silycristin and taxifolin were investigated.RESULTS The optimal conditions were determined to be 1 ∶ 3 for combined carrier ratio,and 1 ∶ 5 for drug-carrier ratio.These five constituents displayed much higher dissolution rates in solid dispersions than those in raw medicine and physical mixture (silymarin-carrier).CONCLUSION Solid dispersions can significantly increase the dissolution rates of effective components in silymarin.

The preparation and in vitro release of a controlled release diclofenac sodium tablet / 中国药学杂志

OBJECTIVE:To prepare diclofenac sodium controlled release tablet,and to evaluate the mechanism of drug release.METHODS:Stearic acid and ethyl cellulose were used as blocking agents and sodium carboxylmethyl starch was used as disintegrating agent.Tablets were made after drying the granules prepared.The dissolution rates were acquired according to Chinese Pharmacopoeia(1995).RESULTS:Drug release from the tablets prepared was of zero-order release before 90% of drug released.No significant influences were observed from the dissolution rates of the different pressure of tablet(5～10kg),amount of drugs contained in the tablet(35%～60%)and different geometry of the tablets,respectively.The remarkable difference waw observed between the disintegrating and blocking agents contained in the tablets.CONCLUSION:The time of 50% of durg released could be changed as the amount of disintegrating or blocking agents were changed.