Vol 53, No 8 (2019)

Specific binding of the sigma-1 receptor (Sigma1R) ligand [³H]-(+)-pentazocine was determined in the P2 and P3 fractions of brain homogenates from inbred BALB/c and C57BL/6 mice after emotional stress in the open-field (OF) test and outbred CD-1 mice after administration of the anxiolytic afobazole. Exposure in the OF test increased specific binding of [³H]-(+)-pentazocine to the P3 fraction of BALB/c mice brain homogenates as characterized by catatonia in the OF test and did not affect ligand binding in C57BL/6 mice with active behavior in the OF test. Afobazole at a dose of 5 mg/kg increased specific binding of [³H]-(+)-pentazocine to the P2 fraction of outbred CD-1 mice brain homogenates. The results indicated that Sigma1R was involved in the formation mechanism of emotional stress responses and in afobazole pharmacodynamics.

Current risks from resistance, adverse drug reactions, and drug – drug interactions of clarithromycin used as a component of Helicobacter pylori eradication therapy are reviewed. The acid sensitivity of clarithromycin i responsible for the dependence of its pharmacological properties on the efficacy of proton-pump inhibitors, which could be one reason for the resistance of H. pylori to the macrolide. The potential for clarithromycin drug – drug interactions is related to its metabolism by CYP3A4 and strong inhibition of this enzyme.

Results from an interspecies scaling study of the elimination half-lives of the anxiolytic GB-115 and the antipsychotic dilept in rats, rabbits, and humans are presented. The elimination half-lives of the studied drugs are calculated in real (chronological) and corrected time (pharmacokinetic). Elimination half-lives in animals and volunteers are compared. Rabbits are found to be a better scaling model for GB-115 although a single preference for dilept was not found.

A series of 1-(2-aminopropyl)-5-aryl-4-acyl-3-hydroxy-3-pyrrolin-2-ones were synthesized by three-component reactions of 4-substituted 2,4-dioxobutanoic acid methyl esters with mixtures of an aromatic aldehyde and 1,2-diaminopropane. Products of their reactions with hydrazine, p-phenetidine, and acetic anhydride were obtained. The analgesic, anti-inflammatory, and antimicrobial activities and hemostatic effect of several compounds were studied.

In the present study we analyze the synthesis as well as biotransformation pathways and metabolic stability of 4-fluoro- N -(1-{2-[2-(methylsulfanyl)phenoxy]ethyl}pyrrolidin-3-yl) benzene sulfonamide – thioether compound 5, with the affinity for several subtypes of the serotonin and dopamine receptor. Studies were conducted in vitro on liver microsomes from three species – mouse, rat, and human. The biotransformation was analyzed using liquid chromatography coupled with mass spectrometry. Two major metabolites (M1 and M2) – products of S-oxidation of the parent molecule – were generated both by in silico and in vitro methods. Use of three species allowed us to determine the interspecies differences in metabolic stability of tested compound. Two parameters, t_0.5 and Cl_int , were calculated. Compound 5 was the most stable in human liver microsomes. Results are useful for understanding the interspecies differences in metabolism of the serotonin and dopamine receptor ligand associated with sulfur atom.

In order to develop high-quality pharmaceutical products, a traditional approach based the univariate or trial and error method was used in the past that led to several problems like non-reproducible, high-cost, and time consuming methods. To overcome these drawbacks, a new concept of the Design of Experiment (DoE) was introduced. DoE is a statistical element of the Quality by Design (QbD) approach introduced by British statistician Sir Ronald Fisher in 1925. The basic objectives of DoE are screening, optimization, and robustness. It involves the execution of experimental design on the basis of suitable variables along with statistical evaluation of obtained responses and exploration of the design space using mathematical or graphical approach. The statistical evaluation empowers to build up the quality of finished products and helps to meet the increasing demands for product of superior quality and standards. This article mainly focuses on the applications of DoE in pharmaceutical product development along with its objectives, design, and selection criteria.

Lysozyme incorporated in polymer solutions is shown to be stabilized during prolonged storage at low temperatures (0 – 4°C) for 12 months with 96% preservation of the hydrolytic activity. Variations of the pH and temperature activity profiles of the enzyme incorporated in polymer solutions promotes its activation under physiological conditions during acidosis associated with inflammations of various etiologies and upon development of dry eye syndrome. Investigation of the biochemical and physicochemical properties of a lysozyme-containing solution showed that the developed eye drops met requirements applicable to them (density, viscosity, osmolality, refractive index, sterility). Ophthalmic safety studies showed that the solution was non-allergenic.

Two different literature methods were used to compare the experimental efficacy and accuracy of dabigatran assays in blood of 30 patients with knee replacements. Blood plasma was collected from patients who underwent anticoagulant therapy and were administered the medicine at a dose of 220 mg. Residual and peak dabigatran concentrations were determined by HPLC-MS and HPLC-MS/MS.

2-Isobutyl-4,6-dimethyl-5-hydroxypyrimidine (SNK-411) and its salt (SNK-578) were synthesized. Antitumor and antimetastatic activity of the new derivative 5-hydroxypyrimidine SNK-578 were studied in tests on male C57BL/6 mice using the B16 melanoma model. The standard grafted dose was 5 × 10⁶ tumor cells mouse. SNK-578 was injected i.p. at doses of 10 and 25 mg/kg for two weeks from day 2 to day 15 of B16 melanoma development. Doxorubicin was injected to mice at a dose of 4 mg/kg on day 2 of tumor development to act as a positive control and to reveal an additive effect from combined single use of doxorubicin and injection of a course of SNK-578. The combination of i.p. injection of a course of SNK-578 at a dose of 10 mg/kg and a single i.p. injection of doxorubicin at a dose of 4 mg/kg revealed statistically significant tumor growth inhibition that was expressed as a decrease of tumor volume by 2.4, 1.9, and 1.5 times on day 11, 15, and 21 of the test as compared with the active control group that did not receive SNK-578. SNK-578 possessed pronounced antimetastatic activity at doses of 10 and 25 mg/kg for monotherapy and coadministration with doxorubicin at a dose of 4 mg/kg. The metastasis inhibition index (MII) after SNK-578 injection at a dose of 10 mg/kg was 75.8%; at 25 mg/kg, 92.3%. The most pronounced antimetastatic effect was observed after combined i.p. injection of SNK-578 at a dose of 10 mg/kg for 14 d and a single injection of doxorubicin at a dose of 4 mg/kg. Metastases were not observed in six of nine mice on day 21 of B16 melanoma development; the other three had 1, 2, and 3 very small metastases so that the MII was 98.9%.

An HPLC-UV method for arbutin determination in bearberry leaves was developed. The conditions were selected. The main metrological characteristics were evaluated. The developed method was shown to be highly efficient and promising and could be recommended for arbutin determination in bearberry leaves as an alternative to the existing pharmacopoeial titration method.

A scheme for developing an excipient composition for liquid dosage forms based on monoclonal antibodies(mAbs) is proposed and used to develop a stable formulation of an active pharmaceutical ingredient (API) and finished dosage form (FDF) for s.c. injection of mAbs IgG1 against a tumor necrosis factor (TNF-α) with API concentrations from 50 to 150 mg/mL.

US FDA requirements published in the new 2018 guidance for bioanalytical method validation and the necessity to confirm their reliability for determining analyte concentrations are reviewed. The history of regulations for bioanalytical method validation is briefly described. The key changes and additions to the FDA guidance for bioanalytical method validation that include unified requirements for chromatographic and ligand-binding method validation, instructions for biomarker validation, a separate section focused on new technologies (e.g., dry blood-spot method), and introduction of the fit-for-purpose concept are discussed. FDA and EAEU requirements for validation of chromatographic assay parameters are compared. In general, the requirements of the new FDA guidance and the EAEU agree despite several differences in the number of parameters and their acceptance criteria.