Determination of plasma tranexamic acid using cation-exchange high-performance liquid chromatography with fluorescence detection

Derivatization of tranexamic acid for its rapid spectrofluorimetric determination in pure form and pharmaceutical formulations: Application in human plasma

An ingenious approach for determination of tranexamic acid spectrofluorimetrically has been developed. This experiment is very simple, sensitive and selective method for determination of tranexamic acid in pure form, pharmaceutical dosage forms and in spiked human plasma. All optimal conditions needed in our proposed experiment have been determined and validated precisely. This developed method based on the reaction between the primary amino group found in the chemical structure of tranexamic acid with the fluorescamine reagent in presence of borate buffer (pH 8.3) that result in the formation of fluorescence product measured at 473.5 nm after excitation at 392 nm. We notice that the linearity of the resulted calibration curve found to be (0.1-0.9 μg/mL) with LOD and LOQ results were 0.0237 and 0.0719 respectively. The validation of the developed method is according to the international council for Harmonization (ICH) guidelines indicating good accuracy and precision. Finally, the developed method has been applied for in vitro study of tranexamic acid by making spiked human plasma with a mean percentage recovery 99.430 ± 0.623 as well as in its pharmaceutical dosage forms tablets and ampoules.

Simple, rapid, and sensitive liquid chromatography-fluorescence method for the quantification of tranexamic acid in blood

Tranexamic acid (TA) is a synthetic antifibrinolytic agent that is being considered as a candidate adjuvant drug for site-specific pharmaco-laser therapy of port wine stains. For drug utility studies, a high-performance liquid chromatography (HPLC)-fluorescence method was developed for the quantification of TA in blood. Platelet-poor plasma was prepared, size-separated using 3kDa cut-off centrifuge filters, and derivatized with naphthalene-2-3-dicarboxaldehyde (NDA) and cyanide. The excess of NDA was quenched after 2 min by adding tryptophan. The derivatives were separated on a 2.1mm C18 column using an acetate buffer/acetonitrile gradient. Excellent separation from plasma background was obtained at pH 5.5. Quantification was carried out at 440/520 nm. The limit of detection was 0.5 microM and the mean+/-SD recovery from whole blood was 81.7+/-10.9%. Derivatized TA samples were stable for at least 36 h at 4 degrees C. The method was successfully applied to a heat-induced TA release study from thermosensitive liposomes.

An ionizable chromophoric reagent for the analysis of primary amine-containing drugs by capillary electrophoresis

We found that ofloxacin acyl chloride is a potential chromophoric reagent for labeling amino analytes for capillary electrophoresis. Ofloxacin acyl chloride has a tertiary amino function in its structure and the derivatives from ofloxacin acyl chloride reacting with amino analytes can be ionized by an acid treatment and analyzed by simple capillary zone electrophoresis. Ofloxacin acyl chloride was used to derivatize model analytes (without chromophore) of amantadine (amino drug), tranexamic acid (non-protein amino carboxylic acid), glycine, and methionine (protein amino acids). The resulting derivatives were analyzed by capillary zone electrophoresis with ultraviolet detection (300 nm). The detection limits of the analytes studied were in the range of 1.0-2.5 microM (S/N = 3, injection 3 s). The precision (relative standard deviation) and accuracy (relative error) of the method for intra- and inter-day analyses of the analytes were respectively below 4.5% and 3.9%. Application of the method to the analysis of tranexamic acid in plasma proved feasible.

Liquid chromatography-tandem mass spectrometry method for the determination of tranexamic acid in human plasma

A new method for the determination of tranexamic acid (TA) in human plasma using high performance liquid chromatography with tandem mass spectrometric detection was described. TA and the internal standard, methyldopa, was extracted from a 200 l plasma sample by a one-step deproteination using perchloric acid. Chromatographic separation was performed on an Xtrra MS C18 Column (2.1 mm x 100 mm, 3.5 microm) with the mobile phase consisting of 10% acetonitrile in 2 mM ammonium acetate buffer (pH 3.5) at a flow rate of 0.15 ml/min. The total run time was 5 min for each sample. Detection and quantitation was performed by the mass spectrometer using the multiple reaction monitoring of the precursor-product ion pair m/z 158 --> 95 for TA and m/z 212 --> 166 for methyldopa, respectively. The method was linear over the concentration range of 0.02-10.00 g/ml with lower limit of quantification of 0.02 microg/ml for TA. The intra- and inter-day precision was less than 11% and accuracy ranged -10.88 to 11.35% at the TA concentrations tested. The present method provides a relatively simple and sensitive assay with short turn-around time. The method has been successfully applied to a clinical pharmacokinetic study of TA in 12 healthy subjects.

Measurement of plasma catecholamines by high-performance liquid chromatography with electrochemical detection in intensive care patients after dobutamine infusion

A procedure for the determination of plasma catecholamine concentrations in critical care patients after dobutamine infusion is presented. A modified chromatographic system is required with an additional washing procedure to achieve maximum sensitivity and stable chromatographic conditions. The influence of storage time on the catecholamine concentrations of plasma samples is reported in detail. A time-dependent decrease in catecholamine concentrations of up to 12 and 39% was found within two and ten months, respectively.

Benefits and risks of antifibrinolytic therapy in the management of ruptured intracranial aneurysms. A double-blind placebo-controlled study

One hundred patients with a verified subarachnoid haemorrhage were studied in a double blind, placebo-controlled trial at a single centre to determine the value and relative risks of tranexamic acid (TXA) in the management of ruptured intracranial aneurysms. The incidence of recurrent haemorrhage between active and placebo groups was identical (12%) and the mortality from recurrent haemorrhage was 7% and 5%, respectively. The overall incidence of cerebral infarction before surgery, at discharge and at 6 months follow-up was greater in the TXA group (27%) than in the control group (11%). Post-operative cerebral ischaemia was significantly more frequent in the active, 18 of 29 as compared to 6 of 32 patients, in the placebo group. In a fifth of the patients in whom cerebral blood flow was estimated there was a significant reduction of cerebral blood flow (CBF) on the side of the ruptured aneurysm in the TXA treated group. It is suggested that this may be the cause of the increased incidence of cerebral ischaemia in this group. There was no significant difference in the incidence of cerebral vasospasm, hydrocephalus, visual disturbances and gastrointestinal disturbances. More fatalities were encountered from ischaemia and recurrent haemorrhage in the TXA group but these differences did not reach statistical significance at the 5% level. Given that disability was due to either vasospasm or recurrent haemorrhage than a patient under TXA treatment was significantly more likely to have disability due to vasospasm (p less than 0.04); the reverse was true for the placebo patient (p less than 0.05).

Polyamine levels in red blood cells from patient groups of different sex and age

Interpretation of polyamine levels found in the tissues and red blood cells of tumour patients has been plagued by the wide variations seen in the concentrations when estimated in groups of either tumour or control patients. To ascertain whether the patient's age or sex were contributing factors, red blood cell polyamine concentrations of 117 control patients were examined by high-performance liquid chromatography. Concentrations of spermidine were consistently higher than those of spermine. Also, regression analysis showed that spermidine and spermine levels tended to change with age and sex, though these trends were statistically non-significant.

Red blood cell polyamines as a diagnostic indicator of glioma presence and recurrence

Red blood cell (RBC) polyamines, spermine and spermidine have been assayed from 103 patients with confirmed intracranial tumours and 87 controls. For spermine the test had a specificity of 97% and a sensitivity of 30% in preoperative patients, increasing to 40% in glioma patients. Tumour recurrence in postoperative patients gave a sensitivity of 48% increasing to 60% in glioma groups. For initial tumour presentation, therefore, this test is suggestive, though not unequivocal, of tumour presence. Its major role probably lies in monitoring the progress of the patient and its major importance in the detection of tumour recurrence.

Determination of tranexamic acid in human serum by high-performance liquid chromatography using selective pre-column derivatization with phenyl isothiocyanate

A high-performance liquid chromatographic method for determination of tranexamic acid in human serum using a selective derivatization has been developed. Tranexamic acid in the sample was allowed to react with phenyl isothiocyanate to form the phenylthiocarbamoyl derivative. Interfering alpha-amino acids in the sample were eliminated by selective derivatization to phenylthiohydantoin derivatives by acid treatment of the phenylthiocarbamoyl derivatives followed by solvent extraction. Then, the sample was analysed by conventional high-performance liquid chromatography with ultraviolet detection. The limit of detection of this method for serum sample was 0.2 micrograms/ml at a signal-to-noise ratio of 2. This method gave results comparable with those obtained by amino acid analysis (regression line: y = 0.4531x-0.02596, r = 0.9998, n = 21).

Estimation of plasma catecholamines by high-performance liquid chromatography with electrochemical detection in patients with subarachnoid haemorrhage

Plasma catecholamine levels were determined by high-performance liquid chromatography with electrochemical detection following alumina extraction. Mean individual recoveries of 50.5, 49.9 and 48% were obtained for norepinephrine, epinephrine and dopamine, respectively, and the limits of detection for each catecholamine were 0.15, 0.34 and 0.6 pmol/ml. Total analysis time for each plasma sample was approximately 1 h. Catecholamine levels were measured in plasma from control subjects and the ranges obtained were: norepinephrine, 0.33-5.98 pmol/ml; epinephrine, 0-4.77 pmol/ml; dopamine, 0-0.8 pmol/ml. When patients with subarachnoid haemorrhage were investigated, the ranges were found to be: norepinephrine, 0.23-7.27 pmol/ml; epinephrine, 0-4.91 pmol/ml; dopamine, 0-0.23 pmol/ml.