Biomedical subjects

Limei Zhao

Publications and source records attributed to Limei Zhao.

4 recordsLinked to original sources

PubMed2007

Determination of miglitol in human plasma by liquid chromatography/tandem mass spectrometry.

A rapid and sensitive method for the determination of miglitol in human plasma using voglibose as internal standard has been developed and validated. Samples of plasma were deproteinated with acetonitrile and washed with dichloromethane before being analyzed by reversed-phase high-performance liquid chromatography (HPLC). Separation was carried out on a short Nucleosil C(18) column (5 microm, 50 x 4.6 mm i.d.) using 10 mmol/L ammonium acetate at 1.0 mL/min as mobile phase. The detector was an Applied Biosystems Sciex API 4000 mass spectrometer using atmospheric pressure chemical ionization (APCI) for ion production. The instrument was operated at unit resolution in the multiple reaction monitoring mode. The assay was linear over the range 5.00-2000 ng/mL with a limit of detection of 1.00 ng/mL. Intra- and inter-day precision were <2.82% and <2.92%, respectively, with accuracy of 93.3-106%. The assay was successfully applied to a clinical pharmacokinetic study of miglitol given as a single oral dose (50 mg) to healthy volunteers.

1-Deoxynojirimycin↗

PubMed2005

Rapid and sensitive liquid chromatography-tandem mass spectrometry method for the quantitation of levodropropizine in human plasma.

A rapid and sensitive LC-MS-MS method for quantifying levodropropizine in human plasma after oral administration of a single-dose (60 mg/day) was developed and validated. The sample preparation used liquid-liquid extraction with a mixture of dichloromethane-diethyl ether (2:3, v/v) in a basic environment. The retention time of levodropropizne and zolmitriptan (used as internal standard) was 1.6 and 1.4 min, respectively. The assay was linear over the range 0.25-500 ng/mL with a LOQ of 0.25 ng/mL. The intra- and inter-day precision were < 8.1% and < 11.5%, respectively, and the accuracy was in the range 87.6-112%. The levodropropizine concentration profile in human plasma was determined.

Antitussive Agents↗

PubMed2004

Development of a dissolution medium for nimodipine tablets based on bioavailability evaluation.

A marked difference in the dissolution rate between two brands of nimodipine tablets was observed using a newly developed dissolution medium of pH 4.5 acetate buffer containing 0.05% sodium dodecyl sulfate (SDS). However, when pH 4.5 acetate buffer containing 0.3% SDS was used as dissolution medium, which was specified in the edition, the dissolution results of the both brands conformed to the BP requirements and no significant difference in dissolution was observed. The dissolution data obtained for two commercial brands of nimodipine tablets indicate the superiority of the proposed system as a discriminatory dissolution medium for nimodipine tablets. The relative bioavailability of the two brands of nimodipine tablets was determined in healthy adult volunteers after a single dose in a randomized crossover study. Plasma concentrations were determined by a liquid chromatography-tandem mass spectrometry method. Statistical comparison of the AUC(0-T), AUC(0- infinity), C(max), and T(max) indicated a significant difference in the two brands of nimodipine tablets.

Adult↗

PubMed2002

[Association of plasminogen activator inhibitor-1 gene 4G/5G polymorphism and coronary heart disease in Chinese patients].

OBJECTIVE: To assess whether the plasminogen activator inhibitor-1 (PAI-1) gene 4G/5G polymorphism is associated with coronary heart disease (CHD) in Chinese patients. METHODS: PAI-1 gene 4G /5G polymorphism was analyzed in normal group (121 individuals) and CHD group (126 cases) by a combination of polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). RESULTS: The 4G allele and 4G/4G genotype frequencies of PAI-1 gene (0.60 and 0.397) for CHD patients were higher than those (0.48 and 0.190) for healthy controls(chi-square=7.63 P<0.01; chi-square=12.67, P<0.01). The odds ratios(OR) for CHD in subjects with the 5G/5G (and 4G/5G) genotypes were 2.54 (95% CI 1.22-5.27, P<0.05) and 1.28(95% CI 1.45-2.38, P>0.05), respectively. CONCLUSION: These results suggest that the PAI-1 4G/4G genotype is associated with an increased risk for CHD in Chinese patients. The subjects with the 4G/4G genotype had a higher prevalence of CHD, compared to those with the 5G/5G PAI-1 genotype.

Adult↗