The prevalence of GERD in most European countries and the Russian Federation is at the level of 15–20%. Hydrochloric acid plays a significant and sometimes major role in damage to the mucosa of the upper gastrointestinal tract (GIT) in patients with various acid-related diseases. Despite the presence of various classes of drugs that reduce the damaging effect of hydro-chloric acid on the mucous membrane of the upper gastrointestinal tract, acid-related diseases continues to be an urgent medical problem. The review article discusses the issues of pharmacological treatment of acid-related diseases. Such classes of drugs as antacids, H2-histamine blockers, gastroprotectors, potassium-competitive blockers of hydrochloric acid secretion are described in detail. Particular attention is paid to the group of proton pump inhibitors (PPIs). The paper evaluates the merits of each class of drugs, their significance in the treatment of acid-related diseases. One of the most popular PPIs in the Russian Federation is omeprazole. The effectiveness of the drug is determined by pharmacokinetic parameters, in particular bioavailability. The bioavailability of omeprazole of various trade names varies widely. To increase the rate and completeness of dissolution, and hence the bioavailability of poorly soluble molecules in the modern pharmaceutical industry, various disintegrants are used as excipients. The addition of sodium superdisintegrant carboxymethyl starch to the new Omez® dosage form with MiniCaps technology promotes an accelerated and more complete intake of omeprazole into the systemic circulation, helping to increase bioavailability. In addition, the innovative dosage form has a volume that is 30% smaller than the classic capsule, which improves ease of use and adherence to treatment.

Helicobacter pylori infection can serve as one of indications to clarithromycin prescription. H. pylori eradication is performed commonly as a treatment for diseases caused by this pathogen and conditions with an increased risk of complications (precancerous changes of the gastric mucosa, unspecified iron deficiency anemia, idiopathic thrombocytopenic purpura, long-term NSAIDs use, anti-platelet drugs use etc). A number of H. pylori functional characteristics determines specific requirements for eradication schemes: high sensitivity of the pathogen, the ability of antibacterial drugs to penetrate and accumulate in gastric tissue and mucous,a stimulation of microorganism’s reproduction and protection of acid-resistant drugs by reducing gastric acid production as well. If the latter is provided by the use of proton pump inhibitors, then clarithromycin fully provides the other issues above. In Russia, standard triple therapy is used as the first-line treatment of H. pylori infection due to current clarithromycin resistance less than 15%. The article gives detailed reasoning and factual evidence of commitment to the first-line therapy under the increasing prevalence of the most recent antibiotic resistance (local resistance to levofloxacin has reached 20%), the high potential for multi-drug resistant H. pylori strains appearing, low ensuring medical facilities with relevant resistance test-systems, a role of generic drugs (clarithromycin and proton pump inhibitors) with compromised pharmaceutical characteristics in creation and erroneous interpretation of a pseudoresistance to clarithromycin.

The relationship between dissolution and bioavailability is an example of the interdependency between the quality of a medicinal product and its safety and efficacy. The uniqueness of thioctic acid is that it can exist in an oxidised and a reduced form, showing lipophilic (lipoic acid) and hydrophilic (dihydrolipoic acid) properties. Bioavailability studies of thioctic acid are necessary to evaluate the expected therapeutic effect and mitigate side effects of the medicinal product.The aim of the study was to carry out equivalence dissolution testing to compare the release of thioctic acid from medicinal products produced by several manufacturers.Materials and methods: the study used a reference medicinal product and three multisource medicinal products by different manufacturers; more specifically, film-coated tablets containing 600 mg of thioctic acid. The experiment was carried out in dissolution media at pH of 6.8±0.05 and 1.2±0.05. Statistical analysis was performed by calculating the average amounts of the substance dissolved, the standard deviation (SD), and the relative standard deviation (RSD, %) using Microsoft Office Excel 2007.Results: The authors chose the testing conditions (dissolution media pH values of 6.8±0.05 and 1.2±0.05) taking into account the nature and characteristics of thioctic acid. The comparison of thioctic acid release profiles based on the calculation of the similarity factor (f2) showed that the dissolution profiles of multisource medicinal products 2 and 3 at pH 6.8 were equivalent to that of the reference medicinal product (more than 85% of the active pharmaceutical ingredient released within 15 minutes) and the dissolution profile of multisource medicinal product 1 was not equivalent to it (with f2 of 28).Conclusions: the established differences in the rate and degree of active ingredient release from the studied medicinal products may indicate possible differences in their pharmacological effectiveness in vivo.

This article analyzes the application of the method for determining the activity of CYP3A4 by determining the concentration of endogenous cholesterol and its metabolite/4-hydroxycholine in blood plasma. It also provides information on the convergence assessment of data obtained using alternative methods for determining the activity of the same CYP450 isoenzyme (CYP3A4) using different substrates: cholesterol and cortisol.