High-performance liquid chromatographic method for the determination of dextropropoxyphene and nordextropropoxyphene in serum

Synthesis of new d-propoxyphene derivatives and the development of a microparticle-based immunoassay for the detection of propoxyphene and norpropoxyphene

The synthesis of [S-(R,S)]-4-[[methyl[2-methyl-3-(1-oxopropoxy)-3, 4-diphenylbutyl]amino]-1-oxobutoxy]-2,5-pyrrolidinedione+ ++ (propoxyphene active ester, 2) is described. This was used as an intermediate to prepare a propoxyphene immunogen, [S-(R,S)]-4-[methyl][2-methyl-3-(1-oxopropoxy)-3,4-diphenylbuty l]-amino]- 1-oxobutyl-Bovine Thyroglobulin (3). This immunogen was then used to generate antibodies which demonstrate good cross-reactivity to d-propoxyphene, d-norpropoxyphene, and other propoxyphene metabolites. In addition, these antibodies were shown to have very low cross-reactivity to methadone, a structurally related compound. The introduction of an aminomethyl benzoate spacer into the propoxyphene active ester (2), followed by the activation of the carboxylic acid, provided for a more stable active ester (5). This stable active ester, together with the antibodies generated from the propoxyphene immunogen, has led to the development of an immunoassay based on the Kinetic Interaction of Microparticles in Solution (KIMS).

Determination of dextropropoxyphene and norpropoxyphene in plasma by high-performance liquid chromatography

A simple and sensitive procedure for the routine assay of the analgesic drug dextropropoxyphene and its main metabolite, norpropoxyphene, in plasma is described. After liquid-liquid extraction from alkalinized plasma and back-extraction into a small volume of an acidic aqueous phase, the aqueous phase was injected into a column packed with 3-microns octadecylsilica particles. Ultraviolet absorbance detection at 210 nm was used. Concentrations down to 2 nM could be determined for both compounds; at this level, the intra-assay coefficient of variation was 5%.

Dopamine and dobutamine reduce myocardial d-propoxyphene content in experimentally intoxicated rats

The effect of sympathomimetic intervention with dopamine or dobutamine on the myocardial uptake of d-propoxyphene was investigated experimentally in rats. The d-propoxyphene (19 mg kg-1 h-1) was continuously infused, intravenously, over 45 min. After 20 min of infusion the rats were given either dopamine (12.5 micrograms kg-1 min-1 or 25 micrograms kg-1 min-1), dobutamine (25 micrograms kg-1 min-1 or 45 micrograms kg-1 min-1) or normal saline (control). Each group consisted of eight rats. The myocardial d-propoxyphene content was significantly lower in the two groups given dopamine and in the group given dobutamine 45 micrograms kg-1 min-1 than in the control group (P less than 0.05). This finding indicates the benefit of early sympathomimetic intervention with either dopamine or dobutamine in d-propoxyphene intoxication.

Cardiovascular function measured by ultrasound Doppler in healthy young men after ingestion of dextropropoxyphene napsylat

In a double blind cross-over study 10 healthy male volunteers were given either 300 mg dextropropoxyphene napsylat (DP) or placebo daily for 16 days. The serum levels of DP and the metabolite nordextropropoxyphene were measured on day 3, 6 and 16. Haemodynamic measurements were made on day 1 and day 16, both at rest and during exercise. The measurements were made non-invasively, with a pulsed ultrasound Doppler. Blood pressure, heart rate, velocity, cardiac output, left cardiac work, increased during work, but showing no significant differences between the groups. The systolic time intervals were also measured by the ultrasound Doppler. The preejection period increased significantly in the DP-group, whereas the ratio preejection period/left ventricular ejection time which reflects the contractility of the heart did not differ significantly. It is concluded that DP taken daily in a normal dose for 16 days did not affect the heart function in healthy young men.

Simultaneous high-performance liquid chromatographic determination of propoxyphene and acetaminophen in pharmaceutical preparations

A normal-phase high-performance liquid chromatographic method, using a 3.3 cm x 4.6 mm silica column (3 microns packing) and an ammonium hydroxide-methanol-dichloromethane mobile phase, has been developed to separate propoxyphene and acetaminophen in less than 5 min. Quantitative recovery of both compounds from various pharmaceutical preparations was achieved, following a single dilution scheme. The method is stable, reproducible, and selective.

Retention behaviour of acidic, neutral and basic drugs on a CN column using phosphate buffers in the mobile phase

The retention behaviour of a set of sixteen more or less drugs on a CN column with methanol-phosphate buffer as eluent was studied. The influence of the volume percentage of methanol, pH and the ionic strength on the capacity factors (k') of the drugs was determined using an experimental design consisting of three pH values (3, 5 and 7), four ionic strengths (0.025, 0.05, 0.075 and 0.1) and three volume percentages of methanol (10, 30 and 50%). The selected drugs were basic, acidic and neutral compounds with different polarity properties. The number of carbon atoms, considered here as reflecting the hydrophobic characteristics of the solutes, varied from 7 to 25. The influence on the retention of drugs on a CN column of the different parameters studied was evaluated. The volume percentage of organic modifier and the pH are the most important factors. A change in ionic strength is important only when large molecules are chromatographed. As the interaction between pH, ionic strength and volume percentage of methanol is small, optimization of the three parameters separately is possible.

A HPLC method for the simultaneous determination of disopyramide, lidocaine and their monodealkylated metabolites

This paper describes a simple high-performance liquid chromatographic method for the determination of disopyramide and lidocaine simultaneously with their dealkylated metabolites. After basic tert-butyl methyl ether extraction and back-extraction with phosphoric acid, the drugs and their metabolites were injected into a Supelcosil CN column and the absorbance of the eluate was measured at 215 nm. The sensitivity was 0.3 mumol/l and the obtained precision, selectivity and stability during storage were adequate for the performed clinical studies in patients therapeutically treated with disopyramide and/or lidocaine. Some results from the clinical studies are briefly presented.