Determination of reboxetine, a recent antidepressant drug, in human plasma by means of two high-performance liquid chromatography methods

Fluvoxamine is an antidepressant drug introduced into the clinic in 1986. It acts by selectively inhibiting neuronal serotonin recapture. It can be quantified by several meth ods, including high performance liquid chromatography. The HPLC method used so far needs special equipment and has poor sensitivity. The technique is difficult and time consuming. An easier, quicker and more sensitive HPLC assay for the routine determination of fluvoxamine in human plasma has therefore been developed. After alkalinisation and direct extraction by a mixture of n-hexane-isoamylic alcohol 985: 15 (v/v) of plasma samples, the organic phases were further extracted by HCl 0.1 N. Thirty μL of the final extract (with loxapine as internal standard) were injected directly into a C-8 column with a mobile phase consisting of 370 mL acetonitrile, 0.4 mL diethylamine, 630 mL of distilled water, 25 mL pic B5. UV detection at 254 nm was used. The whole process was completed in 40 min. The detec tion limit was 10 ng mL-1. No interference was found either with several benzodiazepines or with antidepres sant drugs commonly associated during treatments.

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Developing a High-performance Liquid Chromatography Method for Simultaneous Determination of Loratadine and its Metabolite Desloratadine in Human Plasma

Current Drug Metabolism ◽

10.2174/1389200220666191125095648 ◽

2020 ◽

Vol 20 (13) ◽

pp. 1053-1059

Author(s):

Mahmoud M. Sebaiy ◽

Noha I. Ziedan

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Human Plasma ◽

High Performance ◽

Allergic Diseases ◽

Reversed Phase ◽

Hplc Method ◽

H1 Receptor ◽

Chromatography Method

Background: Allergic diseases are considered as the major burden on public health with increased prevalence globally. Histamine H1-receptor antagonists are the foremost commonly used drugs in the treatment of allergic disorders. The target drug in this study, loratadine, belongs to this class of drugs and its biometabolite desloratadine which is also a non-sedating H1 receptor antagonist with anti-histaminic activity being 2.5 to 4 times greater than loratadine. This study aimed to develop and validate a novel isocratic Reversed-phase High-Performance Liquid Chromatography (RP-HPLC) method for rapid and simultaneous separation and determination of loratadine and its metabolite, desloratadine in human plasma. Methods: The drug extraction method from plasma was based on protein precipitation technique. The separation was carried out on a Thermo Scientific BDS Hypersil C18 column (5μm, 250 x 4.60 mm) in a mobile phase of MeOH: 0.025M KH2PO4 adjusted to pH 3.50 using orthophosphoric acid (85: 15, v/v) at an ambient temperature. The flow rate was maintained at 1 mL/min and maximum absorption was measured using the PDA detector at 248 nm. Results: The retention times of loratadine and desloratadine in plasma samples were recorded to be 4.10 and 5.08 minutes, respectively, indicating a short analysis time. Limits of detection were found to be 1.80 and 1.97 ng/mL for loratadine and desloratadine, respectively, showing a high degree of sensitivity of the method. The method was then validated according to FDA guidelines for the determination of the two analytes in human plasma. Conclusion: The results obtained indicate that the proposed method is rapid, sensitive in the nanogram range, accurate, selective, robust and reproducible compared to other reported methods.

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