Quantitative high-performance liquid chromatographic, gas chromatographic, and gas chromatographic-mass spectrometric analysis of ticlopidine in baboon plasma after solid-phase extraction

Quantitative nondestructive methods for the determination of ticlopidine in tablets using reflectance near-infrared and Fourier transform Raman spectroscopy

Two different nondestructive spectroscopy methods based on near-infrared (NIR) and Fourier transform (FT) Raman spectroscopy were developed for the determination of ticlopidine-hydrochloride (TCL) in pharmaceutical formulations and the results were compared to those obtained by high-performance liquid chromatography (HPLC). An NIR assay was performed by reflectance over the 850-1700 nm region using a partial least squares (PLS) prediction model, while the absolute FT-Raman intensity of TCL's most intense vibration was used for constructing the calibration curve. For both methodologies the spectra were obtained from the as-received film-coated tablets of TCL. The two quantitative techniques were built using five "manual compressed" tablets containing different concentrations and validated by evaluating the calibration model as well as the accuracy and precision. The models were applied to commercial preparations (Ticlid). The results were compared to those obtained from the application of HPLC using the methodology described by "Sanofi Research Department" and were found to be in excellent agreement, proving that NIR, using fiber-optic probes, and FT-Raman spectroscopy can be used for the fast and reliable determination of the major component in pharmaceutical analysis.

Analytical approach to determine ticlopidine in post-mortem blood

A new and sensitive method to determine ticlopidine in whole human blood using proadifen as the internal standard (IS) is described. The analyte and IS were extracted by solid-phase extraction using Oasis HLB cartridges, and the extracts were analyzed by gas chromatography-electron impact ionisation-mass spectrometry (GC/EI-MS). Calibration curves were established daily in spiked blood samples using a non-linear calibration model, between 0.01 and 4.5 microg/mL. The correlation coefficients were higher than 0.995. Precision and accuracy fulfilled the internationally accepted criteria (coefficients of variation were less than 9%, and the measured concentrations were within +/-7% of the true value). Limits of detection and quantitation were respectively, 3 and 10 ng/mL. No interfering substances were detected by analysis of 10 blank blood samples of different origin. Mean recovery, calculated at three concentration levels, was 71%. Because of its simplicity and speed, the proposed method can be applied in the determination of this inhibitor of platelet aggregation in whole blood samples, and is suitable for application in toxicology routine analysis.

Ticlopidine quantification in human plasma by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry. Application to bioequivalence study

A rapid, sensitive and specific method to quantify ticlopidine in human plasma using clopidogrel as the internal standard (IS) is described. The analyte and the IS were extracted from acidified plasma by liquid-liquid extraction using diethyl ether-hexane (80 : 20, v/v). The extracts were analyzed by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry (HPLC/MS/MS). Chromatography was performed isocratically on a Jones Genesis C(8) 4 microm analytical column (150 x 4.1 mm i.d.). The method had a chromatographic run time of 3.0 min and a linear calibration curve over the range 1.0-1000 ng ml(-1) (r(2) > 0.999427). The limit of quantification was 1.0 ng ml(-1). This HPLC/MS/MS procedure was used to assess the bioequivalence of two ticlopidine 250 mg tablet formulations (ticlopidine test formulation from Apotex do Brasil, Brazil, and Ticlid from Sanofi-Synthelabo, standard reference formulation). A single 250 mg dose of each formulation was administered to healthy volunteers. The study was conducted using an open, randomized, two-period crossover design with a 2 week washout interval. Since the 90% confidence interval for C(max) and area under the curve ratios were all inside the 80-125% interval proposed by the US Food and Drug Administration, it was concluded that ticlopidine formulation from Apotex do Brasil is bioequivalent to Ticlid formulation with respect to both the rate and the extent of absorption.

Determination of ticlopidine in human plasma by capillary gas chromatography with ion trap detection

A gas chromatographic method for determination of ticlopidine in human plasma using mass spectrometric detection was developed. A Perkin Elmer model 8500 gas chromatograph coupled to an ion trap detector (ITD) in electron impact mode (EI) was used. The gas chromatograph was fitted with a 30 m x 0.32 mm i.d., DB-17 capillary column with a film thickness of 0.25 microm. The compounds were isolated from plasma by Extrelut-1 solid-phase extraction using hexane as the solvent of elution. The detection and quantification limits for this method were 0.005 and 0.01 microg/ml, respectively. The calibration curves were linear from 0.01 and 2.5 microg/ml. Recoveries from human plasma spiked at 0.01 and 2.0 microg/ml ranged from 84.4 and 87.3%. The coefficient of variation (CV) was between 5.1 and 6.9%. The results show that the sensitivity, accuracy and precision of the method are adequate for the determination of ticlopidine in human plasma samples. The ITD in SIM mode allows the unequivocal identification of ticlopidine. The suitability of this method was evaluated in the determination of ticlopidine in plasma from healthy volunteers following oral administration of a dose of 500 mg/day.

A stability study of ticlopidine products from 18 countries

The results of the stability study of ticlopidine formulations (250 mg and 100 mg) show that products available in many countries worldwide exhibit different stability characteristics. Stability testing under the International Conference on Harmonization (ICH) accelerated test conditions (40 degrees C/75% relative humidity [RH], 3 and 6 months) was performed on a total of 43 products obtained from 18 countries. The samples were visually examined for physical change and analyzed for their content of degradation products, remaining ticlopidine, and in vitro dissolution characteristics (in the case of tablets). Only 6 (16%) of all the samples submitted to this study had a good stability profile. Their appearance remained unchanged during the study; assay results were between 95% and 100%; their impurity content did not exceed 0.25%; and in the dissolution test, at least 75% of ticlopidine was dissolved after 30 min. Three samples had excellent dissolution properties and showed a very high purity level (viz. 21, 40, and 43) over the course of the study.

Liquid chromatographic method for the determination of ticlopidine in human plasma

A simple high-performance liquid chromatographic method for determination of ticlopidine in human plasma using ultra violet detection was developed. The separation of the investigated compound and internal standard was achieved on a C18 BD column with a 0.01 M potassium dihydrogen phosphate buffer (pH 4)-acetonitrile-methanol (20:40:40, v/v) mobile phase. The detection was performed at 215 nm. The compounds were isolated from plasma by Bond Elut C18 solid-phase extraction, the mean absolute recovery was 84.9%. The limit of quantitation was 10 ng ml(-1), the limit of detection was 5 ng ml(-1). The bioanalytical method was validated with respect to linearity, within- and between-day accuracy and precision. system suitability and stability. All validated parameters were found to be within the internationally required limits. The developed analytical method for ticlopidine was found to be suitable for application in pharmacokinetic studies and human drug monitoring.

Pharmacokinetics and effect of ticlopidine on platelet aggregation in subjects with normal and impaired renal function

The pharmacokinetics and the effect of ticlopidine on platelet aggregation were determined in patients with chronic renal failure (n = 6), who were not on dialysis and had glomerular filtration of 16.9 +/- 4.4 mL/min, and were matched with the pharmacokinetics and effects in healthy volunteers (n = 7). Participants were studied after acute oral administration of ticlopidine at the beginning of the study and after 36 days of treatment with 250 mg twice daily. For unchanged ticlopidine there were no significant differences between the concentration profiles for the two study groups. By day 36 the minimum concentrations in plasma were identical (0.35 +/- 0.22 mg/L and 0.36 +/- 0.21 mg/L, respectively). Using 14C-labeled ticlopidine, the concentration profiles of radioactivity on day 1 were similar to those on day 36 for both groups. However, maximum concentrations and area under the concentration-time curve at 72 hours were both higher in patients with renal failure than in healthy volunteers. Treatment with ticlopidine progressively decreased sensitivity to adenosine diphosphate-induced platelet aggregation. At day 36, the concentration of adenosine diphosphate required to achieve 50% platelet aggregation was approximately 2.5 times greater than before treatment. Both patients and healthy volunteers exhibited closely comparable changes. The response to collagen-induced platelet aggregation was not changed in patients by treatment with ticlopidine. In contrast, volunteers required a three- to fourfold increase in collagen concentration to achieve 50% platelet aggregation after 36 days of therapy. Although some differences in both pharmacokinetics and pharmacodynamics of ticlopidine have been demonstrated between patients and and healthy volunteers, results in this study demonstrated that a change of dosage is not required in renal failure.

Determination of ticlopidine in human plasma by high-performance liquid chromatography and ultraviolet absorbance detection

A simple HPLC method has been developed for the determination of ticlopidine in human plasma. Plasma samples were buffered at pH 9 and extracted with n-heptane-isoamyl alcohol (98.5:1.5, v/v). Imipramine was used as internal standard. Chromatography was performed isocratically with acetonitrile-methanol-0.05 M KH2PO4 (20:25:55, v/v) at pH 3.0 containing 3% triethylamine at a flow-rate of 1 ml/min. A reversed-phase column, Supelcosil LC-8-DB, 15 cm x 4.6 mm I.D., 5 microns particle size, was used. The effluent was monitored by UV absorbance detection at 235 nm. The method showed good accuracy, precision and linearity in the concentration range 5-1200 ng/ml. The limit of quantitation was 5 ng/ml, with a precision (C.V.) of 8.91%, which is the same as that achieved by other authors with a previously published GC-MS method. The procedure described in this paper is simple and allows the routine assessment of ticlopidine plasma concentration in pharmacokinetic studies following therapeutic doses in human subjects.

Analysis of ticlopidine and related impurities by capillary electrophoresis

Capillary electrophoresis has been used to analyse ticlopidine and its main impurities in bulk material. The minimum detectable amount of impurities was determined and the electrophoretic conditions used were discussed. The proposed method is also suitable to analyse the drug in plasma.