[Show abstract][Hide abstract] ABSTRACT: Da-Cheng-Qi decoction (DCQD) is composed of dahuang, houpu, zhishi and mangxiao, while Xiao-Cheng-Qi decoction (XCQD) just contains dahuang, houpu, and zhishi. A validated high-performance liquid chromatographic (HPLC) method was developed for the determination and pharmacokinetic comparison of rhein in rats. It was performed on a reversed-phase C(18) column (150 x 4.6 mm) with a mobile phase of methanol and 0.2% acetic acid (89:11, v/v) and ultraviolet detection at 254 nm. The assay was linear over the range 30-3000 ng/mL (r(2) = 0.9991), with mean percentage recovery of 101.4%. The RSD of intra- and inter-day precision were less than 3.0%, with accuracy in the range 96.8-102.5% for each of the concentrations tested. Following oral administration, rhein plasma levels revealed curves characterized by peaks at 20.5 and 30.1 min corresponding to dosages of 15 mg/kg (XCQD) and 20 mg/kg (DCQD) at mean concentrations of 1184.67 and 1814.27 ng/mL, respectively. The half-lives of rhein from XCQD and DCQD were 45.3 and 139.6 min, respectively. AUC(0-12h) of rhein after oral dosage with XCQD and DCQD were 3435.68 and 5382.25 microg/L h, respectively. The pharmacokinetic parameters may be used to guide the clinical prescription compatibility of traditional Chinese prescriptions related to dahuang and mangxiao.
No preview · Article · Nov 2007 · Biomedical Chromatography
[Show abstract][Hide abstract] ABSTRACT: A validated high-performance liquid chromatography (HPLC) method was developed for simultaneous determination and pharmacokinetic study of aloe emodin and chrysophanol in rats. It was performed on a reverse-phase C(18) column and a mobile phase made up of methanol and 0.2% acetic acid (83:17, v/v). The ultraviolet detection was 254 nm. 1,8-dihydroxyanthraquinone was used as the internal standard. The assay was linear over the range 28-2800 ng/mL (r(2) = 0.9993) for aloe emodin and 25.6-2560 ng/mL (r(2) = 0.9991) for chrysophanol. The average percentage recoveries of three spiked plasmas were 98.8-104.8% and 97.7-103.2% for aloe emodin and chrysophanol, respectively. Their RSD of intra-day and inter-day precision at concentrations of 56, 280 and 1400 ng/mL for aloe emodin and 51.6, 258 and 1290 ng/mL for chrysophanol were less than 3.5%. This method was applied for the first time to simultaneously determinate aloe emodin and chrysophanol in rats following oral administration of traditional Chinese medicine of Da-Cheng-Qi decoction. The pharmacokinetic parameters showed that chrysophanol was better absorbed with higher concentrations in plasma than aloe emodin did. They both eliminated slowly in male rats. The assay is suitable for identifying the plasma and tissue levels of aloe emodin and chrysophanol in preclinical investigations.
No preview · Article · Jul 2007 · Biomedical Chromatography