Selective determination of sultopride in human plasma using high-performance liquid chromatography with ultraviolet detection and particle beam mass spectrometry

Development and Validation of a UPLC Method by the QbD-Approach for the Estimation of Rabeprazole and Levosulpiride from Capsules

Statistical experimental design was used to optimize the chromatographic separations of two pharmaceutical compounds from their respective potential impurities. A fractional factorial design was utilized to study the effects of pH, organic solvent in mobile phases A&B, and flow rate on the resolution of Rabeprazole and Rabeprazole Sulfone, which had closely eluting peaks. A desirability function applied to the optimized conditions predicted the peak resolution between 2.2 and 2.7 for the Rabeprazole & Rabeprazole Sulfone impurity. The chromatographic method employed an Acquity UPLC, BEH C18 column (100 × 2.1 mm i.d., 1.7 μm particle size) with the mobile phase consisting of a phosphate buffer, pH 6.5, and acetonitrile in a gradient program. The flow rate and injection volumes were 0.45 mL/min & 5 μl, respectively, and detection was done at 254 nm. The chromatographic method was validated for linearity, accuracy, precision, specificity, and ruggedness according to ICH guidelines. The results clearly showed that the quality by design concept could be effectively applied to optimize a UPLC chromatographic method with fewer trials and error-free experimentation.

Development and Validation of Micellar-Enhanced Spectrofluorimetric Method for Determination of Sulpiride in Pharmaceutical Formulations and Biological Samples

Sensitive and simple spectrofluorometric method has been developed and validated for the quantification of sulpiride in pure, commercial formulations, human plasma and urine in the presence of sodium dodecyl sulphate (SDS) surfactant micelle. The experimental parameters like buffer, surfactant type and volume were studied. A linear relationship was found between sulpiride concentration and fluorescence intensity in the range of 0.02 μg mL–1–7.0 μg mL–1 containing 0.2 M sodium dodecyl sulphate with λex 292 nm and λem 343 nm with a correlation coefficient of 0.9987. The limit of detection (LOD) and limit of quantification (LOQ) was found to be 1.9 × 10–2 μg mL–1 and 5.9 × 10–2 μg mL–1 respectively. The proposed method was successfully applied for the determination of sulphiride in pure and dosage form; the percentage recoveries agreed well with the label value. The effect of common excipients used as additive in pharmaceutical formulations was studied and no interferences was found. Similarly the effect of some common cations and compounds present in urine and plasma were also investigated and the method was found free of interferences. The method was further extended to the in-vitro determination of sulphiride in spiked human plasma and urine samples with percentage recoveries from 98.33%–99.75% and 95.67%–101.67% respectively. The results of the proposed method have been compared with the literature HPLC method and no significant difference was found between them.

High-performance liquid chromatographic determination of tiapride and its phase I metabolite in blood plasma using tandem UV photodiode-array and fluorescence detection

New bioanalytical SPE-HPLC-PDA-FL method for the determination of the neuroleptic drug tiapride and its N-desethyl metabolite was developed, validated and applied to xenobiochemical and pharmacokinetic studies in humans and animals. The sample preparation process involved solid-phase extraction of diluted plasma spiked with sulpiride (an internal standard) using SPE cartridges DSC-PH Supelco, USA. Chromatographic separation of the extracts was performed on a Discovery HS F5 250 mm × 4 mm (Supelco) column containing pentafluorophenylpropylsilyl silica gel. Mobile phase (acetonitrile-0.01 M phosphate buffer pH=3, flow rate 1 ml min(-1)) in the gradient mode was employed in the HPLC analysis. Tandem UV photodiode-array→fluorescence detection was used for the determination of the analytes. Low concentrations of tiapride and N-desethyl tiapride were determined using a more selective fluorescence detector (λ(exc.)/λ(emiss.)=232 nm/334 nm), high concentrations (500-6000 pmol ml(-1)) using a UV PDA detector at 212 nm with a linear response. Each HPLC run lasted 15 min. Lower limits of quantification (LLOQ) for tiapride (N-desethyl tiapride) were found to be 8.24 pmol ml(-1) (10.11 pmol ml(-1)). The recoveries of tiapride ranged from 89.3 to 94.3%, 81.7 to 86.8% for internal standard sulpiride and 90.9 to 91.8% for N-desethyl tiapride.

Development and validation of amisulpride in human plasma by HPLC coupled with tandem mass spectrometry and its application to a pharmacokinetic study

In this study, authors developed a simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantification of Amisulpride in human plasma using Amisulpride-d(5) as an internal standard (IS). Chromatographic separation was performed on Zorbax Bonus-RP C18, 4.6 × 75 mm, 3.5 μm column with an isocratic mobile phase composed of 0.2% formic acid:methanol (35:65 v/v), at a flow-rate of 0.5 mL/min. Amisulpride, Amisulpride-d(5) was detected at m/z 370.1→242.1 and 375.1→242.1. The drug and the IS were extracted by a liquid-liquid extraction method. The method was validated over a linear concentration range of 2.0-2500.0 ng/mL for Amisulpride with a correlation coefficient of (r(2)) ≥ 0.9982. This method demonstrated intra- and inter-day precision within 0.9 to 1.7 and 1.5 to 2.8 % and intra- and inter-day accuracy within 98.3 to 101.5 and 96.0 to 101.0 % for Amisulpride. Amisulpride was found to be stable at 3 freeze-thaw cycles, bench top and auto sampler stability studies. The developed method was successfully applied to a pharmacokinetic study.

Current role of LC-MS in therapeutic drug monitoring

The role of liquid chromatography coupled with mass spectrometry (LC-MS) techniques in routine therapeutic drug monitoring activity is becoming increasingly important. This paper reviews LC-MS methods published in the last few years for certain classes of drugs subject to therapeutic drug monitoring: immunosuppressants, antifungal drugs, antiretroviral drugs, antidepressants and antipsychotics. For each class of compounds, we focussed on the most interesting methods and evaluated the current role of LC-MS in therapeutic drug monitoring.

Simultaneous electrochemiluminescence determination of sulpiride and tiapride by capillary electrophoresis with cyclodextrin additives

Sulpiride and tiapride are often used in the treatment of depression, schizophrenia and psychopathology of senescence, gastric or duodenal ulcers and are also partly excreted by kidney. This work developed a simple and sensitive method for their simultaneous monitoring in human urine based on capillary electrophoresis coupled with electrochemiluminescence detection by end-column mode. beta-Cyclodextrin (beta-CD) was used as an additive to the running buffer to obtain the absolute separation of sulpiride and tiapride. Under optimized conditions the proposed method displayed a linear range from 1.0 x 10(-7) to 1.0 x 10(-4) M for both sulpiride and tiapride with the correlation coefficients more than 0.995 (n = 6). Their limits of detection were 1.0 x 10(-8) M (45 amol) and 1.5 x 10(-8) M (68 amol) at a signal to noise ratio of 3, respectively. The relative standard deviations for six determinations of 2.0 microM sulpiride and 3.0 microM tiapride were 1.8 and 2.5%, respectively. For practical application an extract step with ethyl acetate at pH 11 was performed to eliminate the influence of ionic strength in sample. The recoveries of sulpiride and tiapride at different levels in human urine were between 84 and 95%, which showed that the method was valuable in clinical and biochemical laboratories for monitoring sulpiride and tiapride for various purposes.

Development of HPLC method for the determination of levosulpiride in human plasma

A rapid and simple high performance liquid chromatography (HPLC) method was developed and validated for determination of levosulpiride in human plasma. After extraction with ethylacetate/methylene chloride (5:1, v/v), analysis of levosulpiride in plasma samples was carried out using a reverse phase C18 column with fluorescence detector (maximum excitation at 300 nm and maximum emission at 365 nm) for separation and quantification. A mixture of methanol-20 mM phosphate buffer (pH 3.5, 16:84, v/v) was used as a mobile phase. The method was specific and sensitive with a limit of quantification of 5 ng/ml. This HPLC method was validated by examining the precision and accuracy for inter- and intra-day analysis in the concentration range of 5-150 ng/ml. The relative standard deviation (R.S.D.) in inter- and intra-day validation were 8.16-19.75 and 3.90-11.69%, respectively. In stability tests, levosulpiride in human plasma was stable during the storage and assay procedure. The method was applied to the bioequivalence study of two levosulpiride tablet formulations (25 mg) after a single oral administration.

Establishment of enzyme immunoassay for measuring serum sultopride levels

Measurement of serum sultopride levels was performed using an enzyme immunoassay. Little or no cross-reactivity with metabolites of sultopride and other drugs was found. The results of reproducibility, recovery, and dilution testing were all good enough for clinical use. A comparison between the measurement values of this method (y) with that of high-performance liquid chromatography (x) showed high correlation (n = 211, r = 0.991, p < 0.0001, y = 0.99x + 107.5). In a comparison between the sultopride dose and serum levels in 161 patients, interindividual differences were large (19 times for same doses), implying that the serum level cannot be predicted from the dosage. The method was found to be reliable for serum level measurements of sultopride and useful for monitoring compliance and assessing the optimal dose.

Liquid chromatography-mass spectrometry in forensic toxicology

Liquid chromatography-mass spectrometry has evolved from a topic of mainly research interest into a routinely usable tool in various application fields. With the advent of new ionization approaches, especially atmospheric pressure, the technique has established itself firmly in many areas of research. Although many applications prove that LC-MS is a valuable complementary analytical tool to GC-MS and has the potential to largely extend the application field of mass spectrometry to hitherto "MS-phobic" molecules, we must recognize that the use of LC-MS in forensic toxicology remains relatively rare. This rarity is all the more surprising because forensic toxicologists find themselves often confronted with the daunting task of actually searching for evidence materials on a scientific basis without any indication of the direction in which to search. Through the years, mass spectrometry, mainly in the GC-MS form, has gained a leading role in the way such quandaries are tackled. The advent of robust, bioanalytically compatible combinations of liquid chromatographic separation with mass spectrometric detection really opens new perspectives in terms of mass spectrometric identification of difficult molecules (e.g., polar metabolites) or biopolymers with toxicological relevance, high throughput, and versatility. Of course, analytical toxicologists are generally mass spectrometry users rather than mass spectrometrists, and this difference certainly explains the slow start of LC-MS in this field. Nevertheless, some valuable applications have been published, and it seems that the introduction of the more universal atmospheric pressure ionization interfaces really has boosted interests. This review presents an overview of what has been realized in forensic toxicological LC-MS. After a short introduction into LC-MS interfacing operational characteristics (or limitations), it covers applications that range from illicit drugs to often abused prescription medicines and some natural poisons. As such, we hope it can act as an appetizer to those involved in forensic toxicology but still hesitating to invest in LC-MS.