Biomedical subjects

Yuen-Fan Wong

Publications and source records attributed to Yuen-Fan Wong.

3 recordsLinked to original sources

PubMed2006

Combinative method using HPLC quantitative and qualitative analyses for quality consistency assessment of a herbal medicinal preparation.

A selective and efficient quality consistency assessment system was developed for monitoring the manufacturing processes of a Chinese herbal preparation, qingfu guanjieshu (QFGJS) capsule, and for assessing its stability over time. This system is based on quantitative determination of four marker compounds, i.e., sinomenine, paeoniflorin, paeonol, and curcumin, and on qualitative fingerprinting analysis of QFGJS using high-performance liquid chromatography-photodiode array detection (HPLC-DAD) method. The separation was performed on a Phenomenex ODS column by gradient elution with acetonitrile and aqueous phase (containing 0.1% phosphoric acid, adjusted with triethylamine to pH 3.5+/-0.2) at a flow-rate of 1.0 ml/min. In fingerprinting analysis, the chemical characteristics of four herbs present in QFGJS (excluding radix Aconiti Lateralis Preparata) were present in the HPLC chromatographic file. In addition, quantitative determination of hypaconitine was carried out with our published HPLC method as a supplement for quality control of the radix Aconiti Lateralis Preparata in QFGJS. The results showed that the contents of these five marker compounds and HPLC fingerprint profiles of three batches of QFGJS products collected at 3 months after production in the stability testing were relatively consistent. This well-developed method could be used for quality assessment of the complex preparations of herbal medicine.

Aconitine↗

PubMed2005

The pharmacokinetics and tissue distribution of sinomenine in rats and its protein binding ability in vitro.

Sinomenine, an alkaloid derived from the Chinese medical plant Sinomenium acutum, was studied with regard to its pharmacokinetics and tissue distribution in rats, and to its protein binding ability in the plasma of rats and rabbits and in the solutions of albumin and alpha-1-acid-glycoprotein. An HPLC analytical method was developed for determining sinomenine. The results demonstrated that oral administration with a single dosage at a rate of 90 mg sinomenine/kg in rats achieved about 80% bioavailability, while most of the other pharmacokinetic parameters were similar to the data from the animals treated intravenously. This indicates that oral administration of sinomenine would be appropriate in clinics. In rats, at 45 min after oral dosage, the drug was found to distribute widely in the internal organs, with tissue concentrations (from highest to lowest) in the order of kidneys, liver, lungs, spleen and heart, brain and testicles. At 90 min after dosing, the tissue concentrations in the organs were markedly decreased. The liver and kidneys manifested as the dominant organs with high tissue concentrations that might be responsible for metabolism and elimination of sinomenine. Examination of the protein binding ability showed that sinomenine with 4 microg/ml concentration in the plasma of rats and rabbits or in the albumin solution achieved a protein binding rate of more than 60%, while in the solution of alpha-1-acid-glycoprotein the rate was only about 33%. This result suggests that sinomenine might have much more potent binding ability with albumin than with alpha-1-acid-glycoprotein, resulting from its acidic property.

Administration, Oral↗

PubMedDate not supplied

Quantification of Aconitum alkaloids in aconite roots by a modified RP-HPLC method.

The three Aconitum alkaloids, aconitine (1), mesaconitine (2) and hypaconitine (3), are pharmacologically active but also highly toxic. A standardised method is needed for assessing the levels of these alkaloids in aconite roots in order to ensure the safe use of these plant materials as medicinal herbs. By optimising extraction, separation and measurement conditions, a reliable, reproducible and accurate method for the quantitative determination of all three Aconitum alkaloids in unprocessed and processed aconite roots has been developed. This method should be appropriate for use in the quality control of Aconitum products. The three Aconitum alkaloids were separated by a modified HPLC method employing a C18 column gradient eluted with acetonitrile and ammonium bicarbonate buffer. Quantification of Aconitum alkaloids, detected at 240 nm, in different batches of samples showed that the content of 1, 2 and 3 varied significantly. In general, the alkaloid content of unprocessed roots was higher than that of processed roots. These variations were considered to be the result of differences in species, processing methods and places of origin of the samples.

Aconitine↗