Diazotization titrations in pharmacopoeial quality control of medicines and proposals for their revision in the European Pharmacopoeia.

Based on the data in the Ph. Eur., some other newer pharmacopoeias and published experimental papers propose to revise the text of Ph.

Colour and content of some metals in honey.

The paper highlights the correlations between the results of instrumental colour measurement and the content of certain metals in kinds of honey. Sufficiently close correlations may lead to the development of procedures for the rapid determination of the content of these metals in honey by colour measurement without the need for more demanding sample preparation.

Colour and content of some biologically active substances in honey.

This paper highlights the correlations between instrumental measurements of colour and the content of some biologically active organic compounds (especially phenolics and flavonoids) in honey. Sufficiently close correlations may lead to the development of procedures for rapid determination of the content of these substances in honey by colour measurement without the need for more demanding sample preparation.

Colour and antioxidant activity of honey.

The paper highlights the relationships between the results of instrumental colour measurement and the results of the determination of the antioxidant activity of honey (especially by DPPH and FRAP). The sufficiently close correlations show that once verified, supplemented by regression analysis and calibration, they may find application in the rapid determination of the antioxidant activity of honey.

Telacebec (Q203): Is there a novel effective and safe anti-tuberculosis drug on the horizon?

High prevalence and stronger emergency of various forms of drug-resistant tuberculosis (DR-TB), including the multidrug-resistant (MDR-TB) as well as extensively drug-resistant (XDR-TB) ones, caused by variously resistant Mycobacterium tuberculosis pathogens, make first-line anti-tuberculosis (anti-TB) agents therapeutically more and more ineffective. Therefore, there is an imperative to develop novel highly efficient (synthetic) agents against both drug-sensitive-TB and DR-TB. The exploration of various heterocycles as prospective core scaffolds for the discovery, development and optimization of anti-TB drugs remains an intriguing scientific endeavour.

Telacebec (Q203): Is there a novel effective and safe anti-tuberculosis drug on the horizon?

High prevalence and stronger emergency of various forms of drug-resistant tuberculosis (DR-TB), including the multidrug-resistant (MDR-TB) as well as extensively drug-resistant (XDR-TB) ones, caused by variously resistant Mycobacterium tuberculosis pathogens, make first-line anti-tuberculosis (anti-TB) agents therapeutically more and more ineffective. Therefore, there is an imperative to develop novel highly efficient (synthetic) agents against both drug-sensitive-TB and DR-TB. The exploration of various heterocycles as prospective core scaffolds for the discovery, development and optimization of anti-TB drugs remains an intriguing scientific endeavour.

Analysis of positional isomers of 2-3-4-alkoxyphenylcarbamic acid derivatives by a combination of TLC and IMS.

In this study, we have demonstrated a separation of positional isomers of some derivatives of alkoxyphenylcarbamic acid. These compounds belong to drugs with local anesthetics activity. The low volatility compounds were analysed by a Thin Layer Chromatography (TLC) and Ion Mobility Spectrometry (IMS) using diode laser desorption for sample introduction to IMS.

Colour and content of some biologically active substances in natural products and products of natural origin.

The paper draws attention to the correlations between the results of instrumental colour measurements and the content of some biologically active organic substances (carotenoids, chlorophyll, anthocyanins, curcuminoids, etc.) in natural products and products of natural origin. After supplementation by regression analysis and calibration, sufficiently close correlations can lead to the development of procedures for rapid determination of the content of these substances and their groups by colour measurement without more demanding sample treatment.

Advances in the use of instrumental measurement of colour in the development, production and quality control of drugs, medicinal preparations and pharmaceutical auxiliary substances III.

Colour is an important indicator of the quality of pharmaceuticals, medicinal products and pharmaceutical excipients. The paper summarizes advances in the use of instrumental colour measurement in synthetic medicines and medicines of non-natural origin, their dosage forms and excipients published in 2013-2019.

Chiral Aspects of Local Anesthetics.

Thanks to the progress made in chemical technology (particularly in the methodologies of stereoselective syntheses and analyses) along with regulatory measures, the number of new chiral drugs registered in the form of pure enantiomers has increased over the past decade. In addition, the pharmacological and pharmacokinetic properties of the individual enantiomers of already-introduced racemic drugs are being re-examined. The use of the pure enantiomer of a drug that has been used to date in the form of a racemate is called a "chiral switch".

Focus on perchlozone, an anti-tuberculosis drug from the Russian Federation.

The prevalence of multidrug-resistant tuberculosis (MDR--TB) and extensively drug-resistant tuberculosis (XDR--TB) has been increasing at an alarming rate worldwide. Todays “Fight against Tuberculosis“ programmes in the Russian Federation are subsidized by state and regional governments as well as health authorities. Each region has its own specific characteristics and needs specific interventions.

Theory and practice of pharmacopoeial control of the quality of drugs and excipients VII. The colour reference solutions of the European pharmacopoeia (Ph. Eur.).

Data calculations of three different workplaces consistently show that the difference in colour ΔE (CIELAB) of some colour reference solutions according to Ph. Eur. with small colour and purified water are too small.

Determination of Critical Micellar Concentration of Homologous 2-Alkoxyphenylcarbamoyloxyethyl-Morpholinium Chlorides.

The critical micellar concentrations of selected alkyloxy homologues of local anesthetic 4-(2-{[(2-alkoxyphenyl)carbamoyl]oxy}ethyl)morpholin-4-ium chloride with = 2, 4, 5, 6, 7, 8, and 9 carbons in alkyloxy tail were determined by absorption spectroscopy in the UV⁻vis spectral region with the use of a pyrene probe. Within the homologous series of the studied amphiphilic compounds, the ln() was observed to be dependent linearly on the number of carbon atoms in the hydrophobic tail: ln() = 0.705⁻0.

Determination of dicoumarol in Melilotus officinalis L. by using molecularly imprinted polymer solid-phase extraction coupled with high performance liquid chromatography.

In this work, a method for the extraction of dicoumarol from plant sample utilizing selective adsorbent based on molecularly imprinted polymer was developed. Molecularly imprinted polymer (MIP) was synthesized by bulk polymerization, and on the surface of magnetic particles using dicoumarol as a template, methacrylic acid as functional monomer, chloroform as a porogen, and ethyleneglycol dimethacrylate as a cross-linker. Prepared polymeric materials were evaluated on the base of capacity, selectivity, and morphology.

[Separation of phenylalanine and methionine enantiomers by HPLC method: a comparison of stationary phase types].

The paper deals with enantioselective separation of amino acids by the high performance liquid chromatography method. Separations of enantiomeric forms were tested on the chiral stationary phases based on β-cyclodextrine, isopropyl carbamate cyclofructan 6, and the macrocyclic antibiotic teicoplanin. The best enantioseparation was obtained on the teicoplanin-based chiral stationary phase in the reversed-phase mode.

[Study of local anaesthetics: Part 206* Micellization of selected of quaternary ammonium salt derived from heptacaine].

Micellization of selected quaternary ammonium compounds derived from heptacaine have been studied by absorption spectroscopy in the UV/VIS spectral region with the use of a pyrene probe. The compounds studied in the aqueous solution have been marked as H22, H26, H27, H29, H34, H + Al and H + B and the derivative marked as H34 was studied in a 3 mol/l ethanol solution at the temperature of 25 °C. In the homologous series of the studied bromides H22, H26, H27 and H29, cmc was observed to be dependent on the number of carbon atoms nc in the hydrophobic chain: ln (cmc) = -3.

[Determination of flavonoids in natural materials with HPLC].

The paper reviews recent developments in the determination of flavonoids with HPLC. Flavonoids are a group of polyphenolic compounds commonly found in plants. Sample preparation is a very important step in the analytical procedure.

[Influence of excipients on caffeine permeation from gels].

Unlabelled: The subject of this paper is a study of the influence of excipients on caffeine permeation from dermal semisolids drugs. Due to its advantageous properties, caffeine can be successfully used in dermal hydrogels. The choice of excipients from the group of humectants and cationic surfactants also plays an important role.

[Studies of local anaesthetics: part 205* studies of stability of heptacainium chloride and carbisocainium chloride using an accelerated non-isothermal test].

The paper studies the kinetics of alkaline hydrolysis and stability under non-isothermal conditions of heptacainium chloride and carbisocainium chloride in the medium of aqueous-ethanolic solution of sodium hydroxide c = 0.1 mol/l and buffer solutions of values of pH 7.0 and pH 8.

[Formulation of benzethonium chloride into gels].

This study is focused on the preparation of gels with antimicrobial effects. A quaternary ammonium salt, benzethonium chloride, in a concentration of 0.01-0.

[Advances in the use of instrumental measurement of colour in the development, production and quality control of drugs, medicinal preparations and pharmaceutical auxiliary substances II*].

The paper summarizes the use of instrumental colour measurement in the field of pharmaceuticals of natural origin and other substances of natural origin beneficial for health in recent 10 years. Colour measurement in this field was most frequently employed in the monitoring of various aspects of the process of drying of medicinal plants and their parts.

[Study of local anaesthetics: part 204* determination of critical micelle concentrations of selected derivatives of pyrrolidino-m-alkoxyphenylcarbamic acid using pyrene as a probe].

The critical micelle concentrations of the studied derivatives of pyrrolidino-m-alkoxyphenylcarbamic acid in aqueous media at 25 °C were determined using the UV/VIS absorption spectroscopy method with pyrene as a probe. In the absorption spectra of the derivatives and pyrene, there were examined unmasked pyrene peaks, at wavelength of 336 and 320 nm for VIII Z, XIV Z and XVII Z, and in addition at 308 nm for XXIX Z. The critical micelle concentrations were defined from the plots of the sum of the unmasked pyrene peaks against the surfactant concentration that had a sigmoidal character of Boltzmann type.

[Influence of quaternary ammonium salt on liberation of drug with antiseptic effect].

The paper evaluates the influence of three surfactants (carbetopendecinium halogenides) on the liberation of the drug chlorhexidine dihydrochloride (CHX) in 0.1% (w/w) from the dosage form-gel and also the flow properties of gels. The following tensides were evaluated: carbetopendecinium bromide (SB), carbetopendecinium chloride (SC), and carbetopendecinium iodide (SI).

HPLC determination of saccharides after pre-column derivatization in honey samples.

The work is focused on the quality evaluation of Slovak honey samples on the basis of minor saccharide contents. The samples included unifloral and multifloral types of honeys. The saccharide contents were determined by HPLC with fluorescence detection.

Study of local anaesthetics: part 201. Determination of the critical micellar concentration of pentacaine hydrochloride from the measurements of UV absorption of pyrene in methanol solutions.

The formation of micelles of the local anaesthetic pentacaine hydrochloride (K 1902) in methanol solutions at two concentrations was investigated by measuring the absorbance of pyrene in surfactant solution. The absorbance vs. surfactant concentration profiles for all the major UV spectral peaks of pyrene have been found to be sigmoidal in nature which were analyzed according to Sigmoidal-Boltzmann equation to evaluate the cmcs values of the studied systems.