ABSTRACT
Objective To establish an HPLC method to determine the related substances of metolazone and valsartan in com?pound metolazone tablets. Methods An Agilent Eclipse SB-C18 column (4.6 mm × 250 mm,5 μm) was used with 0.01 mol/L KH2PO4 buffer(pH=3.5)-acetonitrile as the mobile phase with gradient elution at a flow rate of 1.0 ml/min. The column temperature was 30℃ and the detection wavelength was 237 nm. Injection volume was 20 μl. Results Metolazone,valsartan and related sub?stance B of valsartan were separated completely. The calibration curves were linear within the range of 3-30μg/ml for metolazone, 0.1-2.0μg/ml for valsartan and 0.08-2.0μg/ml for related substane B of valsartan. The average recoveries were 102.97%,100.81%and 100.44%,respectively. The repeatability and intermediate precision met with requirements. The test solution was stable within 24 h. Conclusion The method is specific,sensitive,accurate and reliable,thereby can be used for the determination of metolazone and valsartan related substances in compound metolazone tablets.
ABSTRACT
Objective To establish an in vitro accelerated release method of triptorelin acetate microspheres with good in vi-tro/in vivo correlation(IVIVC). Methods The in vivo release of triptorelin acetate from microspheres was obtained by residual method in rats. Influences of pH value,concentration of ethanol,temperature,rotation speed and concentration of antiseptic on the in vitro accel-erated release were studied,then the correlation between in vitro accelerated release and in vivo release of the microspheres was estab-lished by adjusting the release conditions. Results The in vitro accelerated release medium of triptorelin acetate microspheres composed of 15%ethanol solution(containing 0.06%Tween 80 and 0.1%benzalkonium chloride)at 55℃with rotating rate of 200 r/min. The cumulative release of triptorelin acetate from microspheres was 87.35%at 30 h under accelerated release condition,equivalent to in vivo release for 30 days. The established in vitro accelerated release had a good correlation with that of in vivo(y=0.8845x+12.4510, R2=0.9938). Conclusion The in vitro accelerated release of triptorelin acetate microspheres could correlate well with in vivo release and has a potential application in rapid and effective evaluation of triptorelin acetate microspheres.
ABSTRACT
Objective To introduce the operation skills of tail vein injection in conscious rats , and improve the success rate of ingection .Methods The rat was fixed by the operator with a self-made binding clothes , one person assists to fix the rat tail, one person performs puncture , and one person performs injection .During the injection process , we should minimize the injury to the rat tail and the stress caused by operation , strictly limit the needle point , the number of puncture , the maximum dose and injection speed , and to make the needle position away from the injection site to avoid contamination and waste of the drug solution .Results The operation method was successfully established and it was fast , stable, with good repeatability and high degree of coordination .Conclusion This operation is rapid, reliable and stable, worthy of recommendation , especially for the intravenous injection of expensive drugs .