SIMULTANEOUS DETERMINATION OF BENZYDAMINE HYDROCHLORIDE, METHYLPARABEN AND PEPPERMINT OIL IN A SPRAY DOSAGE FORM BY GAS CHROMATOGRAPHY

Objective: To develop and validate an analytical procedure for simultaneous determination of benzydamine hydrochloride, methylparaben and peppermint oil in a spray dosage form by gas chromatography method (GC). Methods: The analytical method was conducted on Agilent 7890 gas chromatograph, equipped with HP-5 capillary column with helium as a mobile phase, split/splitless injector and flame ionization detector and an auto injector. Validation parameters, such as selectivity, linearity, precision, accuracy and, robustness were estimated. Results: A method for simultaneous determination of benzydamine hydrochloride, methylparaben and peppermint oil in a spray dosage form by GC was developed. The retention time of menthol (marker substance of peppermint oil) methylparaben and benzydamine hydrochloride, was 5.0, 9.2, and 19.4 respectively. Relative standard deviation (RSD)% for precision was 0.24, 0.13 and 0.12 respectively. The linearity of the method for given analytes was estimated in a concentration range of 80-120% to a nominal concentration with the respective correlation coefficients of more than 0.999. Accuracy of the method was within 98-102% for all analytes. Conclusion: The developed analytical procedure meets the acceptance criteria of validation parameters and can be used in quality control laboratories for determination of benzydamine hydrochloride, methylparaben and peppermint oil in a spray dosage form

A New Method for Studying the Kinetics of the Release of Poorly Soluble API from Solid Oral Dosage Forms on the Example of Quertin®

In this paper, it is proposed to consider a new method developed for studying the kinetics of release of substances that are poorly soluble in aqueous media on the example of quercetin. The study object was the drug containing plant bioactive components – Quertin® chewable tablets, 40 mg, 3 blisters, 10 pcs – produced by PJSC SIC “Borshchahivskiy CPP”. An Agilent 1290 Infinity II LC System liquid chromatograph with an Agilent 6530 mass selective detector (Agilent Technologies) was used for the analysis. Solubility profiles were studied in accordance with the requirements of the Biopharmaceutical Classification System (BCS). The solubility limit of the substance in the media studied has been determined. A method for the quantitative determination of quercetin in test media in the range of specified concentrations with high sensitivity and selectivity has been developed. The dissolution of Quertin® chewable tablets in 3 different aqueous dissolution media with pH 1.2, pH 4.5 and pH 6.8 was studied, the dissolution profiles were compared, and the f2 factor was calculated. This factor is a criterion for evaluating the study by comparing dissolution kinetics with in vivo results. The results obtained indicate that the approach proposed to studying the kinetics of the release of substances that are sparingly soluble in aqueous solutions allows us to correctly assess the release of such substances in accordance with the requirements of the BCS. The method developed has been validated

Синтез, протимікробна активність та докінгові дослідження 6-(1H-бензімідазол-2- іл)-5-метилтієно[2,3-d]піримідин-4(3H)-онів з ацетамідними та 1,2,4-оксадіазол-5- ілметильними замісниками

Aim. To synthesize, study the antimicrobial activity and suggest antimicrobial activity mechanism for the novel derivatives of 6-(1H-benzimidazol-2-yl)-5-methylthieno[2,3-d]pyrimidin-4(3H)-one. Results and discussion. As the result of the targeted modification of 6-(1H-benzimidazol-2-yl)-5-methylthieno[2,3-d]-pyrimidin-4(3H)-one in position 3 with acetamide and 1,2,4-oxadiazol-5-ylmethyl substituents, the compounds, which demonstrated better antimicrobial activity in the agar well diffusion assay than the reference drug Streptomycin, were obtained. To elucidate the mechanism of action of the novel compounds, the docking studies were con-ducted to the active site of the 16S subunit of ribosomal RNA, the proven target for aminoglycoside antibiotics, as well as tRNA (Guanine37-N1)-methyltransferase (TrmD), which inhibitors were considered as a new potential class of antibiotics. Experimental part. By the interaction of 6-(1H-benzimidazol-2-yl)-5-methylthieno[2,3-d]pyrimidin-4(3H)-one with a series of N-arylchloroacetamides and 3-aryl-5-(chloromethyl)-1,2,4-oxadiazoles in DMF in the presence of K2CO3 the target compounds were obtained. The antimicrobial activity was assessed by the agar well diffusion method. The concentration of microbial cells was determined by the McFarland standard; the value was 107 cells in 1 mL of the media. The 18 – 24 hour culture of microorganisms was used for tests. For the bacteria cultivation, Müller-Hinton agar was used, Sabouraud agar was applied for C. albicans cultivation. The compounds were tested as the DMSO solution with the concentration of 100 µg/mL; the volume of the solution was 0.3 mL, the same volume was used for Streptomycin (the concentration 30 µg/mL). The docking studies were performed using Autodock Vina. Crystallographic data for the complexes of Streptomycin with the 16S subunit of ribosomal RNA (1NTB) and its active site, as well as for tRNA (Guanine37-N1)-methyltransferase (EC 2.1.1.228; TrmD) (5ZHN) and its active site were obtained from the Protein Data Bank.Conclusions. It has been determined that 2-[6-(1H-benzimidazol-2-yl)-5-methyl-4-oxothieno[2,3-d]pyrimidin-3(4H)-yl]-N-[4-(ethoxy)phenyl]acetamide, which is the most active as an antimicrobial agent among the compounds tested, also shows the best binding activity towards the active site of tRNA (guanine37-N1)-methyltransferase.Мета. Синтезувати й дослідити протимікробну активність нових похідних 6-(1H-бензімідазол-2-іл)-5-метилтієно[2,3-d]піримідин-4(3H)-онів та запропонувати механізм протимікробної активності.Результати та їх обговорення. У результаті цілеспрямованої модифікації положення 3 6-(1H-бензімідазол-2-іл)-5-метилтієно[2,3-d]піримідин-4(3H)-ону ацетамідним та 1,2,4-оксадіазол-5-ілметильним замісниками було одержано сполуки з визначеною методом дифузії в агар протимікробною активністю, що є більшою за активність препарату порівняння Стрептоміцину. З метою з’ясування механізму дії синтезованих сполук було проведено докінгові дослідження щодо активного сайту субодиниці 16S рибосомальної РНК, яка є підтвердженою мішенню для аміноглікозидних антибіотиків, а також тРНК (Гуанін-37-N1)-метилтрансферази (TrmD), інгібітори якої розглядаються як новий потенційний клас антибіотиків. Експериментальна частина. Шляхом взаємодії 6-(1H-бензімідазол-2-іл)-5-метилтієно[2,3-d]піримідин-4(3H)-ону з рядом N-арилхлороацетамідів та 3-арил-5-(хлорометил)-1,2,4-оксадіазолів в умовах ДМФА-K2CO3 було одержано цільові сполуки. Антимікробну активність визначали методом дифузії в агар. Концентрацію мікробних клітин визначали за МакФарландом; мікробне навантаження склало 107 мікробних одиниць в 1 мл середовища. Для тестів використовували 18 – 24 годинну культуру мікроорганізмів. Для культивування бактерій використовували агар Мюллера-Гінтона; для культивування C. albicans використовували агар Сабуро. Сполуки вводили методом дифузії в агар (лунками) у вигляді розчину у ДМСО в концентрації 100 мкг/мл в об’ємі 0,3 мл; аналогічний об’єм використовували для Стрептоміцину (конц. 30 мкг/мл). Докінгові дослідження проводили за допомогою програми Autodock Vina. Кристалографічні дані для комплексів стрептоміцину з 16S субодиницею рибосомальної РНК (1NTB) та її активного сайту і для тРНК (Гуанін-37-N1)-метилтрансферази (EC 2.1.1.228; TrmD) (5ZHN) та її активного сайту було отримано з Protein Data Bank.Висновки. Виявлено, що сполука 2-[6-(1H-бензімідазол-2-іл)-5-метил-4-оксотієно[2,3-d]піримідин-3(4H)-іл]-N-[4-(етокси)феніл]ацетамід, яка характеризується найбільшою протимікробною активністю, у докінгових розрахунках є також найбільш ефективним інгібітором тРНК (Гуанін-37-N1)-метилтрансферази

Obtaining the Enoxaparin Sodium Substance Equivalent to the Original Clexane® and Lovenox®. The Selection of Technological Parameters and Optimization of the “Greenness” of the Purification Stage

The aim of the study was to adjust and optimize the purification stage of crude enoxaparin sodium to obtain a substance equivalent to the original drugs Clexane® and Lovenox® according to the criteria specified by the FDA. The purification stage involves the reprecipitation of crude enoxaparin in methanol. Determining the ratio of solvents required for the reprecipitation is important for studying the correlation between the experimental conditions of the technological process and the structural characteristics of enoxaparin samples. In the study, the method of purification of enoxaparin sodium described in the patent was assessed, and the following variations of the MeOH:H2O solvent ratio were selected – 4:1; 2:1; 1:1. The obtained samples of enoxaparin sodium were analyzed according to the in-house specification developed on the basis of the pharmacopoeial monograph, as well as by non-pharmacopoeial methods, such as two-dimensional NMR spectroscopy (HSQC) and size exclusion chromatography (SEC) for detailed characterization of the molecule. Strategies of greening of the enoxaparin sodium purification stage by reducing the E-factor were also considered in the study. Considering the principles of “green” chemistry, the method of purification of crude enoxaparin sodium was optimized by the solvent regeneration. It was experimentally possible to demonstrate the effect of the solvent ratio at the stage of purification of crude enoxaparin on the composition, as well as on the number and distribution of oligosaccharide fractions in the molecule. Based on the results of the study, it can be concluded that the ratio of MeOH:H2O=1:1 allows obtaining samples that are closest to Clexane® and Lovenox® in terms of the molecular weight distribution profile and the composition profile. The E-factor was also reduced from 14 to 5.25 by solvent regeneration

Molecular docking studies of N-substituted 4-methoxy-6-oxo-1-aryl-pyridazine-3-carboxamide derivatives as potential modulators of glutamate receptors

In the present study, the affinity of pyridazine derivatives for the most promising antiparkinsonian biotargets - I-III groups of metabotropic and ionotropic NMDA-glutamate receptors - was evaluate

Modelling and investigation of amoxicillin chemical interaction with mineral waters containing a significant amount of calcium and magnesium salts

In recent years, the interaction of drugs with the components of food and drinks has been actively researched to ensure rational therapy. It is particularly important for amoxicillin as an antibiotic group of drugs, considering the issue of resistance. A study of the interaction of amoxicillin with mineral waters, which in significant quantities may contain cations and anions and enter complexation reactions, has not been conducted before. For the study, various chemical and physicochemical methods were used. Also in vitro dissolution test with conditions of simultaneous administration of amoxicillin with mineral waters in a 0.1M HCl was modelled. Results showed that amoxicillin could form multiple complex compounds with magnesium cations in the 0.1 M HCl with different stoichiometry. The study showed that from several investigated mineral waters, presented on the Ukrainian market, the “Karpatska dzherelna” could interact with amoxicillin in the medium of a 0.1 M HCl

Phytogeographical profiling of ivy leaf (Hedera helix L.)

Leaves of Hedera helix L. have been widely used for the treatment of productive cough and chronic inflammatory bronchitis. The pharmacological effect may be caused by the presence of many active compounds which also may show additively or synergistically action. The quality of raw material, as well as, the pharmacological activity strongly depends on the phytochemical composition thus, phytoprofiling and phytochemical markers identification are essential for the standardization of herbal materials for comprehensive characterization of herbal drugs. The aim of this comparative investigation was to determine the composition of flavonoids, phenolic acids, triterpene saponins, amino acids, and individual fast-acting antioxidants in H. helix leaf samples collected from different climatic and environmental regions of Europe. The determined predominant phenolic compounds and radical scavengers were 3,5-caffeoylquinic acid and chlorogenic acid corresponding up to 80 % of total radical scavenging activity. These compounds could be chosen as analytical markers. The results have revealed two major phytogeographical groups with characteristic phytochemical composition: the central part and the southern part growing sites, with latter having significantly lower amounts of all compounds tested. The determined patterns of bioactive compounds suggest distinct chemotypes with characteristic phenolic acid, flavonoid, triterpene saponin, and amino acid complexes. Developed and validated analytical methods are suitable for fingerprint profiling of the phenolic, radical scavenging, triterpenic compounds, and amino acids and marker elucidation for standardization

Development of the Method of Simultaneous Quantitative Determination of Loratadine and Auxuilary Substances in the Combined Syrup "Loratadin+"

Aim. The aim of the present study was to develop a method for the simultaneous determination of loratadine and auxiliary substances - methyl parahydroxybenzoate and propyl parahydroxybenzoate in the combined "Loratadine+" syrup in the presence of a bupleurum aurus grass extract.Materials and methods. Liquid chromatography separation was performed using a Shimadzu Nexera X2 LC-30AD HPLC system (Shimadzu, Japan) composed of a quaternary pump, an on-line degasser, a column temperature controller, the SIL-30AC autosampler (Shimadzu, Japan); the CTO-20AC thermostat (Shimadzu, Japan) as well as the SPD-M20A diode array detector (DAD).Results and discussion. Identification of the main component and impurities in the combined syrup was performed by determining the retention times of peaks of loratadine, methyl parahydroxybenzoate and propyl parahydroxybenzoate on the chromatogram of the test solution, obtained by quantifying them, which coincided with the retention times of the corresponding peaks on the chromatogram of the reference solution.When developing a quantitative determination method, it was found that using the gradient mode, the best separation between the compounds was observed, the separation coefficient between the peaks of methyl parahydroxybenzoate and the peaks closest to it became more than 2.5, in the case of propyl parahydroxybenzoate this index was more than 3.To confirm the correctness of the proposed method, validation studies were carried out in accordance with the requirements of SPHU. It was established that the uncertainty of sample preparation is 1.5 % for loratadine, 1.47 % for methyl parahydroxybenzoate, and 1.53 % for propyl parahydroxybenzoate, which does not exceed the acceptance criteria. The specificity of the technique was confirmed by comparing the chromatograms of the reference solution, the test solution and the chromatogram of the blank solution. Requirements for the linearity of the method were performed over the entire range of concentrations for loratadine and both excipients. The correlation coefficients were 0.9999, 0.9999 and 0.9995, respectively. The correctness of the technique was carried out according to two criteria - practical and statistical insignificance, which were determined in the course of experimental studies. The results of the assessment of intralaboratory precision showed that the obtained values of the confidence interval of the average result to the criteria of acceptability. Based on the results of the determination of robustness, it was found that for optimal chromatographic conditions, a freshly prepared reference solution can be used within 24 hours.Conclusions. A method was developed for the simultaneous quantitative determination of loratadine and auxiliary substances - methyl parahydroxybenzoate and propyl parahydroxybenzoate in the syrup of "Loratadine+". The conditions that allow to correctly determining all the components in the presence of a bupleurum aurus grass extract were determined. The correctness of the methodology is confirmed by validation studie

Synthesis and anticonvulsant activity of 6-methyl-2-((2-oxo-2-arylethyl)thio)pyrimidin-4(3 H)-one derivatives and products of their cyclization

The alkylation of 6-methyl-2-thioxo-2,3-dihydro-1H-pyrimidine-4-one phenacyl bromides under different conditions was investigated. It was found that during the reaction in the medium of DMF/K2CO3 a mixture of 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one and 3-hydroxy-3-aryl-7-methyl-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-5-one was formed. The holding of the resulting mixture in the concentrated sulphuric acid leads to the formation of cyclization products - derivatives of 3-aryl-7-methyl-5H-thiazolo[3,2-a]pyrimidin-5-one with high yields. Individual S-alkylated derivatives – 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one - were obtained by reacting in methanol in the presence of sodium methoxide. Pharmacological screening of synthesized compounds for anticonvulsant activity on the model of pentylenetetrazole seizures in rats was carried out and some regularity “structure-activity” was established