Therapeutic monitoring of imipramine and desipramine by micellar liquid chromatography with direct injection and electrochemical detection

A micellar liquid chromatographic (MLC) procedure was developed for the clinical monitoring of imipramine and its active metabolite, desipramine. The determination of these highly hydrophobic substances was carried out after direct injection of the serum samples using a mobile phase composed of 0.15 m SDS--6% (v/v) pentanol buffered at pH 7, pumped at 1.5 mL/min into a C(18) column (250 x 4.6 mm), and electrochemical detection at 650 mV. Using this MLC method, calibration was linear (r > 0.995) and the limits of detection (ng/mL) were 0.34 and 0.24 for imipramine and desipramine, respectively. Repeatabilities and intermediate precision were tested at three different concentrations in the calibration range and a CV (%) below 2.2 was obtained. In this MLC procedure, the serum is determined without treatment, thus allowing repeated serial injections without changes in retention factors, and reducing the time and consumables required to carry out the pretreatment process. The assay method can be applied to the routine determination of serum imipramine and its metabolite in therapeutic drug monitoring.     

Formylation of Secondary Amines with Dialkyl Acetals of Dimethylformamide

Abstract

The product of the reaction of dialkyl acetals of N, N-dimethyl-formamide with desipramine has been found to be N-formyldesipramine, and not the N-ethyl derivative as reported earlier. Evidence for the structure was obtained from NMR, IR and mass spectra of the compound as well as comparison with N-formyl and N-ethyldesipramine prepared by alternate routes.     

Simultaneous Determination of Maprotiline,Desipramine, and Moclobemide by Reversed-Phase High-Performance Liquid Chromatography and Statistical Optimization

Abstract

A method for separation of three antidepressants, maprotiline, desipramine, and moclobemide, by reversed-phase high-performance liquid chromatography (RP-HPLC) was developed and validated. To find optimal conditions and estimate the impact of individual parameters on the separation, a complete set of 2³ interdependent relationships of the mobile phase composition, temperature, and the volume flow rate were examined. Full separation of the investigated components from a laboratory mixture was achieved on a Supelcosil LC-18 (120 mm × 4.6 mm, 5 µm) column, using two solvent systems, 3% ammonium ion in water/ethanol and acetonitrile, and alternating isocratic gradient–isocratic elution modes. Relevance of the proposed method for therapeutic drug monitoring is anticipated.     

Synthesis of cobaltocenium salts for use as redox labels and their incorporation into Nafion films

A cobaltocenium label was covalently attached to two antidepressants, nortriptyline and desipramine, via an amide linkage, and also to the hydrazine derivative of the biologically important compound biotin (vitamin H), again via an amide linkage. Analytically pure samples of these new cobaltocenium salts could be obtained by chromatography on silica gel followed by elution with aqueous acetone solutions containing sodium chloride (NaCl). These positively charged cobaltocenium ions preconcentrate in a polyanionic Nafion film coated on a glassy carbon surface, albeit at different concentration levels. One factor which seems to influence the amount of cobaltocenium ion that enters the film is polarity since the cobaltocenium ion containing the rather polar biotin preconcentrates at the lowest level in the relatively hydrophobic Nafion. Square-wave voltammograms of Nafion films containing these cobaltocenium cations exhibit a one-electron, reversible, reduction wave at approximately ?1.1 V (vs Ag/AgCl) with peak currents that are sufficiently large to permit detection of 10^?8 M quantities of these substances in the bulk solution.     

Polycarbonate-coated magnetic nanoparticles for the extraction of imipramine and its primary metabolite from urine

This study introduces a reliable and inexpensive magnetic dispersive solid phase extraction to extract imipramine and its primary metabolite (desipramine) from urine samples. To accomplish this aim, Fe₃O₄ magnetic nanoparticles were synthesized by sonication, subsequently, polycarbonate was precipitated gradually onto the surface of them to form the adsorbent. Extraction recoveries of 85% and 76%, enrichment factors of 57 and 51, limits of detection of 2.5 and 2.8 μg/L, and limits of quantification of 8.3 and 9.3 μg/L were obtained for imipramine and desipramine under the optimal conditions, respectively. In addition, relative standard deviations for intra- (n = 6) and inter-day (n = 5) precisions at two concentrations (50 and 100 μg/L of each analyte) were less than or equal to 4%. Short extraction time, good repeatability, high enrichment factors, and simplicity are the main advantages of the proposed method.