Search

Aim. To develop the unified method of the HPLC analysis of loratadine, which can allow obtaining reliable and reproducible results of the studies of pharmaceuticals and biological matrices for monitoring the treatment effectiveness.
Materials and methods. The HPLC analysis was performed on a “Milichrome A-02” microcolumn liquid chromatograph under the following conditions: a reversed-phase variant, 2 × 75 mm column filled with a non-polar sorbent Prontosil 120-5 C18 AQ, 5 μm; the mobile phase in the mode of a linear gradient – from eluent А (5 % of acetonitrile and 95  % of a buffer solution) to eluent B (100 % of acetonitrile) for 40 min. The flow rate of the mobile phase was 100 μL/min; the injection volume was 4 μL. The multichannel detection of the substance
was carried out using an UV-detector at 210, 220, 230, 240, 250, 260, 280 and 300 nm; the optimal value of the column temperature was 37 – 40 °С, and the pump pressure was 2.8 – 3.2 MPa.
Results and discussion. As a result of the studies performed, the retention parameters of loratadine and spectral relationships were determined using the unified HPLC method. This made it possible to include the results obtained in the database for the identification of antihistamines in the therapeutic monitoring of the treatment with an individual drug or in the complex treatment of allergic reactions. The development of the quantitative determination
of loratadine by HPLC on model solutions using various concentrations of the drug was carried out. The content of loratadine was determined by the equation S = 1.14 × 10-3C – 0.50 × 10-4; the correlation coefficient was 0.9998. It was found that the relative standard deviation RSD did not exceed 0.93 % when analyzing loratadine in the model solutions by HPLC.
Conclusions. The identification and the quantitative determination of loratadine by the unified HPLC method have been conducted. The method allows obtaining reliable and reproducible research results. The results of the studies can be recommended for implementation in the practice of forensic bureaus, toxicological centers, and clinical laboratories.

Aim. To study the qualitative composition, the quantitative content of catechins in green tea leaves and compare the data obtained with those evaluated by spectrophotometry.
Materials and methods. Green tea leaves used for the analysis were collected in Anhui Province, China. The extract for the HPLC analysis was obtained by the maceration method with 60 % ethanol twice in the raw material/extractant ratio of 1 : 20. In the case of the spectrophotometric analysis, green tea leaves were extracted with 70 % ethanol twice by the maceration method in the raw material/extractant ratio of 1 : 20. The analysis of the extract from green tea leaves was performed by high performance liquid chromatography using a Prominence LC-20 Shimadzu chromatographic system (Japan) with a SPD-20AV spectrophotometric detector, an Agilent Technologies Microsorb-MV-150 column (reversed phase, C18 modified silica gel, length – 150 mm, diameter – 4.6 mm, particles size – 5 μm). Substances in the extract were identified by comparing the retention time and the spectral characteristics of the test substances with the same characteristics of the reference standards. Spectrophotometric measurements were carried out using a UV-1000 single beam spectrophotometer (China) with the pair of S90-309Q quartz square cells.
Results and discussion. Using high performance liquid chromatography 5 catechins were identified.
Among them epigallocatechin-3-O-gallate (10.85 %) predominated, while catechin (0.61 %) had the lowest concentration. The total amount of catechins in green tea leaves was 30.56 and 24.79 % by HPLC and spectrophotometry, respectively. The F- and t-tests showed that there was no significant difference between the results of HPLC and spectrophotometry.
Conclusions. The qualitative composition and the quantitative content of catechins have been determined in the extract from green tea leaves by high performance liquid chromatography and spectrophotometry. Both HPLC and spectrophotometric methods can be used to determine the total catechin content in green tea leaves. The high content of catechins makes the extract promising for further study and creation of new herbal medicinal products and dietary supplements. The results obtained will be used for standardization of green tea leaves and for future pharmacological research of its extract.

Aim. To study the qualitative composition and quantitative content of the polyphenolic compounds in Pimpinella anisum herb and determine their antioxidant activity.
Results and discussion. Among the polyphenolic compounds contained in anise herb, chlorogenic acid
(4.409 mg/g) predominates. Signifcant amounts of catechins (3.104 mg/g), apigenin derivatives (3.077 mg/g) and luteolin (1.864 mg/g) also accumulate in the herb. Minor amounts of myricetin (0.105 mg/g) and naringenin (0.019 mg/g) derivatives, rutin (0.189 mg/g), quercetin (0.028 mg/g), apigenin (0.009 mg/g) and hesperetin (0.002 mg/g) are present. According to the research results, the antioxidant activity of polyphenolic compounds of anise herb with reference to ascorbic acid was found to be 67.76 ± 0.05 mmol/g. Rutin exhibited the antioxidant activity at the level of 3979.59 ± 0.08 mmol/g.
Experimental part. Pimpinella anisum herb collected during the flowering stage in the summer of 2019 in
the Kharkiv region (Ukraine) was used for analysis. The analysis of 70 % ethanolic extract from anise herb was performed by high performance liquid chromatography using a Prominence LC-20 Shimadzu chromatographic system (Japan) with a SPD-20AV spectrophotometric detector, an Agilent Technologies Microsorb-MV-150 column (reversedphase, C18 modifed silica gel, length – 150 mm, diameter – 4.6 mm, particles size – 5 μm). Identifcation of substances in the extract was carried out by comparing the retention time and the spectral characteristics of the test substances with the same characteristics of the reference standards. The antioxidant activity was determined by the potentiometric method (pH meter – Hanna 2550, with redox electrode EZDO PO50) with reference to ascorbic acid.
Conclusions. The qualitative composition and quantitative content of polyphenolic compounds in the ethanolic extract of anise herb have been determined by high performance liquid chromatography. The total content of polyphenolic compounds is 17.576 mg/g. The antioxidant activity of polyphenolic compounds of anise herb with reference to ascorbic acid has been found to be 67.76 ± 0.05 mmol/g.
Key words: polyphenolic compounds; anise; herb; high performance liquid chromatography; antioxidant activity

The development of medicines based on alder cone extracts led to the introduction of Altan and Altabor
medicines into medical practice. The technology of extraction cake from cones has made it possible to obtain extracts with different therapeutic properties.
Aim. To develop an effective method for studying the qualitative composition of the Altabor substance and
determine the quantitative content of its components.
Results and discussion. The Altabor substance is a complex mixture of ellagitannins containing more than 70 components. The main components of the extract (or their isomers) were determined by mass spectrometry and by comparing the retention times with the literature data. Gallic, ellagic, valoneic acids dilactone were conclusively determined by adding reference standards of these acids to the extract. The substance contains the following compounds: 2,3-hexahydroxydiphenoyl-(α/β)-glucose t_r1 = 0.55 min, t_r2 = 0.89 min (α and β isomers), 4,6-O-[(S)-valeonyl]-D-glucose (isomer) t_r = 0.64 min, gallic acid t_r = 1.198 min, pedunculagin t_r1 = 3.63 min, t_r2 = 4.62 min
(α and β isomers), proecoxin A (isomer) t_r = 4.78 min, valoneic acid dilactone t_r = 6.19 min, ellagic acid pentoside (isomer) t_r = 7.07 min, ellagic acid t_r = 7.335 min.
Experimental part. The composition analysis was performed using an Agilent 1200 chromatograph with a UV detector, a G6140 mass detector, an Alltech 3300 light scattering detector (ELSD), as well as the Agilent ChemStation Rev.B.04.03 software. The molecular weights of the compounds in the extract were determined using the method of mass spectrometry of ESI-electrospray ionization. The determination of the components was performed using an ultraviolet detector at a wavelength of 280 nm. The column was Rapid Resolution HT Cartige, 4.6 × 30 mm, 1.8 μm, Zorbax SB-C18.
Conclusions. A new effective method of analysis of the Altabor substance has been developed; it allows
determining the qualitative and quantitative content of its structural components. The method gives the possibility to control the process of obtaining the Altabor substance, study the dependence of its composition on the conditions of its obtaining, batch number, place, time of the natural raw material collection, and study the composition of other pharmaceutical substances, the plant raw material containing tannins. The advantage of the method is
the short time (up to 10 min) of analysis using high-performance liquid chromatography at high resolution.
Key words: gallotannins; ellagitannins; Altabor; chemical composition; structure; HPLC (high-performance liquid chromatography)

Aim. To determine the fragmentation pathways of eight 1,2,4-triazole-3-thiones, which are intermediate products in the synthesis of active pharmaceutical ingredients of potential and registered pharmaceutical formulations.

Results and discussion. HPLC-MS analysis of eight 1,2,4-triazole-3-thiones, which are intermediate products in the synthesis of salts of 1,2,4-triazolylthioacetate acids, has been carried out; the mass spectra of the compounds to be analyzed have been registered in ESI-mode with different fragmentor voltage (0, 100, 200 V). The fragmentation pathways and patterns of ion decay for compounds to be analyzed have been proposed.

Experimental part. Agilent 1260 Infinity HPLC System with Agilent 6120 mass spectrometer were used. HPLC-MS conditions: column – 4,6 × 30 mm, reversible phase Zorbax SB C18, 1.8 μm, 40 ^oC; mobile phase – 0.1 % HCOOH in H₂O and 0.1 % HCOOH in СH₃CN in isocratic mode (50:50, v/v); the flow rate – 0.4 mL/min; ion source – API-ES; positive polarity; drying gas – nitrogen (rate – 10 L/min); the capillary voltage – 4000 V; scanning in the range of m/z 100 – 1000.

Conclusions. For the first time it has been interpreted the mass spectra of 1,2,4-triazole-3-thiones series, the intermediate compounds in the synthesis of active pharmaceutical ingredients of pharmaceutical formulations. The fragmentation pathways and patterns of eight 1,2,4-triazole-3-thiones have been shown.

Received: 06.09.2019
Revised: 20.01.2020
Accepted: 27.02.2020

Metronidazole belongs to the group of antiprotozoal medicines and widely used for the treatment of infectious diseases; the medicine has a number of side effects manifested by usual symptoms of acute intoxication, especially when interacting with other drugs and alcohol.
Aim. To apply the system of MiLiChrome® A-02 HPLC-analyzer widely used in the Ukrainian laboratories of forensic toxicology for the metronidazole quantitative determination in biological fluids and carry out validation of the procedures developed.
Materials and methods. The sample preparation of blood and urine was carried out by extraction with acetonitrile and 2-propanol followed by separation of the organic layer under the conditions of the aqueous phase saturation with ammonium sulfate. Previously blood and urine were treated with acids. Isolation was carried out in the strong acid, neutral and weak alkaline medium.
Results and discussion. To find the optimal conditions of the sample preparation such validation parameters as specificity/selectivity and recovery were determined. The results of the blank samples analysis were acceptable for all variants of the sample preparation procedures. Recovery values were reproducible for all procedures of analysis studied, but efficacy of metronidazole isolation was variable – from 85% to 97 %. The results of verification of metronidazole stability showed the necessity to carry out all measurements within 12 hours after obtaining the solutions to be analyzed. The results of determination of linearity, accuracy and precision were the evidence
of acceptable systematic and random errors of the HPLC/UV-procedures studied in the variant of the method of calibration curve, method of standard and method of additions.
Conclusions. The set of HPLC/UV-procedures for the metronidazole quantitative determination in blood and urine has been developed. Validation of the procedures developed has been carried out.