Disposition of enantiomers of sulpiride in humans and rats

Preparation and characterization of a chiral molecularly imprinted polymer with a novel functional monomer for controlled release of S-sulpiride

A novel molecularly imprinted polymer (MIP) with chiral recognition affinity to S-sulpiride (S-SUL) enantiomer was prepared by using newly synthesized N-acryloyl-tryptophan (ATrp) as function monomer, S-SUL as the template molecule, and ethyleneglycol dimethacrylate (EGDMA) as the cross linker. Under the optimized synthesis conditions, the MIP was synthesized by bulk polymerization according to the molar ratio of 1:4 of S-SUL to ATrp, and structurally characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and laser particle analysis. The results illustrated that the MIP offered uniform, loose and porous structure. The adsorption performance of the MIP was evaluated by the isotherm and kinetic models, and the adsorption isotherm conformed to the Freundlich model. The maximum adsorption capacity, selectivity factor and enantioselectivity coefficient to S-SUL were respectively 226.2389 µmol/g, 2.34 and 11.66. Based on the chiral recognition specificity, the drug release experiments demonstrated that the MIP as controlled and sustained release carrier could inhibit the release rate of S-enantiomer compared to the tablet without the MIP, exhibiting the potential of the MIP synthesized in chiral drug delivery.

Quality by design in the chiral separation strategy for the determination of enantiomeric impurities: development of a capillary electrophoresis method based on dual cyclodextrin systems for the analysis of levosulpiride

Quality by design (QbD) concepts, in accordance with International Conference on Harmonisation Pharmaceutical Development guideline Q8(R2), represent an innovative strategy for the development of analytical methods. In this paper QbD principles have been comprehensively applied in the set-up of a capillary electrophoresis method aimed to quantify enantiomeric impurities. The test compound was the chiral drug substance levosulpiride (S-SUL) and the developed method was intended to be used for routine analysis of the pharmaceutical product. The target of analytical QbD approach is to establish a design space (DS) of critical process parameters (CPPs) where the critical quality attributes (CQAs) of the method have been assured to fulfil the desired requirements with a selected probability. QbD can improve the understanding of the enantioseparation process, including both the electrophoretic behavior of enantiomers and their separation, therefore enabling its control. The CQAs were represented by enantioresolution and analysis time. The scouting phase made it possible to select a separation system made by sulfated-β-cyclodextrin and a neutral cyclodextrin, operating in reverse polarity mode. The type of neutral cyclodextrin was included among other CPPs, both instrumental and related to background electrolyte composition, which were evaluated in a screening phase by an asymmetric screening matrix. Response surface methodology was carried out by a Doehlert design and allowed the contour plots to be drawn, highlighting significant interactions between some of the CPPs. DS was defined by applying Monte-Carlo simulations, and corresponded to the following intervals: sulfated-β-cyclodextrin concentration, 9-12 mM; methyl-β-cyclodextrin concentration, 29-38 mM; Britton-Robinson buffer pH, 3.24-3.50; voltage, 12-14 kV. Robustness of the method was examined by a Plackett-Burman matrix and the obtained results, together with system repeatability data, led to define a method control strategy. The method was validated and was finally applied to determine the enantiomeric purity of S-SUL in pharmaceutical dosage forms.

Pharmacokinetics of levosulpiride after single and multiple intramuscular administrations in healthy Chinese volunteers

The main purpose of this study was to evaluate the pharmacokinetics of levosulpiride in humans after single and multiple intramuscular injections. Six males and six females received single dose of either 25 mg or 50 mg levosulpiride, or multiple doses of 25 mg every 12 h for 5 consecutive days. In the single 25 mg study, the mean peak plasma concentration (C_max) was 441 ng/mL, the mean area under the concentration–time curve from 0 to 36 h (AUC_0–36) was 1724 ng h/mL, and the mean elimination half-life (t_1/2) was 7.0 h. In the single 50 mg study, the mean C_max was 823 ng/mL, the mean AUC_0–36 was 3748 ng·h/mL, and the mean t_1/2 was 6.8 h. After multiple doses of 25 mg levosulpiride, the average plasma concentration (C_av) was 136 ng/mL, the fluctuation index (DF) was 3.60, and the accumulation ratio (R) was 1.2. Levosulpiride injections appeared to be well tolerated by the subjects, and can be used for successive administration.

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 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.

Chiral analysis of selected dopamine receptor antagonists in serum using capillary electrophoresis with cyclodextrin additives

Dopamine D-2 receptor antagonists' eticlopride and sulpiride were determined in serum using capillary electrophoresis with cyclodextrin additives. Chiral resolution of S(-) and R(+) sulpiride and eticlopride were achieved using 2% sulfated-beta-cyclodextrin (S-beta-CD) in 20 mM citrate run buffer (pH 2.90). A 72-cm fused silica capillary operated in the reversed polarity mode voltage of 20 kV was used for the analysis. The analytes of interest were isolated from serum using a solid phase extraction procedure with recoveries in excess of 85% for all four enantiomers. The D-2 receptor antagonist (-) butaclamol was used as internal standard. The limits of detection were 0.3 and 0.1 microg/ml for S(-) and R(+) eticlopride and for S(-) and R(+) sulpiride, respectively, in 1 ml of serum. The limits of quantitation were 2 and 1 microg/ml for S(-) and R(+) eticlopride, and for S(-) and R(+) sulpiride, respectively. Calibration curves were linear over the 2-20 micro/ml range for eticlopride and 1-20 microg/ml range for sulpiride. The coefficients of determination were greater than 0.99 (n = 12 for eticlopride and n = 15 for sulpiride). Precision and accuracy of the method were 0.27-6.38 and 0.20-3.60% for S(-) eticlopride, 2.33-4.28 and 0.80-5.73%, for R(+) eticlopride, 3.46-6.84 and 0.80-4.26%, for S(-) sulpiride; and 4.71 -6.47 and 2.00-6.67%, for R(+)-sulpiride, respectively.