[Antioxidant activity of tinctures prepared from hawthorn fruits and motherwort herb]. / Antioxidacní aktivita tinktur pripravených z hlohových plodu a nati srdecníku.

The paper aimed to determine and compare the antioxidant activity of two tinctures and selected flavonoids present in the tinctures. The tinctures were prepared from hawthorn fruits and motherwort herb. The group of selected flavonoids included rutin, quercetin, hyperosid, epicatechine, and procyanidin B2. Two methods were employed to determine antioxidant activities: the inhibition of peroxynitrite-induced nitration of tyrosine was measured, and the ability to quench radicals was examined by of the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). Both tinctures under study were able to quench radicals and reactive forms of oxygen and nitrogen. The motherwort herb tincture was more effective, but no direct effect of phenolic compounds on the extent of antioxidant activity was demonstrated. The total content of polyphenols in the motherwort herb tincture was higher by 163 %, nevertheless antiperoxynitrite activity was higher just by 19 % (p < 0.05), and the ability to reduce DPPH differed in both tinctures in a minimal manner. Of the individual flavonoids, the substances present in the tinctures in higher concentrations contributed most to antioxidant activity. In the hawthorn fruit tincture it was epicatechine and hyperosid, whereas in the motherwort herb tincture it was rutin.

[An orientational examination of the effects of extracts from mixtures of herbal drugs on selected renal functions]. / Orientacní sledování vlivu výluhu ze smesí rostlinných drog na vybrané funkce ledvin.

The paper aimed to determine the effects of mixtures of selected medicinal plants on some physiological renal functions, i.e. excretion of urine and electrolytes and changes in the quantity of prostaglandins E2 (PGE2) and kallikrein-kinins in rat blood plasma after water and salt load. The following medicinal plants were selected for the examination: downy birch (Betula pubescens EHRH.), everlasting flower (Helichrysum arenarium L. MOENCH.), hawthorn (Crataegus oxyacantha L.), woodland strawberry (Fragaria vesca L.), sweet corn (Zea mays L.), German chamomile (Matricaria recutita L.), and field horsetail (Equisetum arvense L.). Herbal drugs were used to compose 6 mixtures. Extracts from these mixtures were administered to Wistar strain males and their effects were compared with the effects of an administered suspension of hydrochlorothiazide, an extract from field horsetail herb alone, and a control group of animals which was not administered any preparation. The greatest diuretic effect was found in a mixture composed of birch leaves (Betulae folium), hawthorn berries (Crataegi fructus), strawberry leaves (Fragariae folium), corn silk (Maydis stigmata), chamomile flowers (Matricariae flos), and horsetail herb (Equiseti herba). Its effect was greater by 47% and 34% than the effect of a horsetail herb extract and a hydrochlorothiazide suspension (p < 0.05), respectively. The extract from this mixture also increased the quantity of prostaglandins E2 and kallikrein-kinins in rat blood plasma in water and salt load.

[A cellulose derivative with a potential to become an active pharmaceutical substance as well as an auxiliary substance]. / Oxycelulosa--celulosový derivát s potenciálem ucinné i pomocné látky.

The review article is focused on one of the wide range of pharmaceutically and medicinally employed cellulose derivates--oxycellulose. This substance, prepared by oxidation of cellulose, in contrast to cellulose esters and ethers, has not been not employed in practice in a wide extent yet. However, recent studies reveal its potential use in modern therapeutical systems, whether as a release-modifying excipient, a drug carrier, or also an active substance with ability of hemostasis, prevention of tissue adhesion after surgical operations, and a substance with antimicrobial and immunomodulating activity, whose unique property of biodegradability, promoted by hypoallergenicity and non-irritability, has not been observed in any of the hitherto used cellulose derivates. The article presents a comprehensive overview about the history of this derivate, from its physico-chemical properties through the description of the ability of biodegradability to its already realized and planned utilization.

[Liquid ginger extract: technology of production and quality evaluation]. / Tekutý zázvorový extrakt: technologie výroby a hodnocení jakosti.

The paper aimed to elaborate the technology of the production of a liquid ginger extract and to select and verify the methods of quality evaluation of the final preparation. The experiment revealed 70% ethanol as a suitable extraction agent. The optimal conditions for the development of an extract of good quality are established when the herbal drug is crushed to form particles passing through a sieve with a mesh size of 4000 microm, the extraction method is repercolation with the division of the charge of the drug in the relation 5:3:2, and the liquid flows from the percolator at a rate of 0.2ml/min/100 g of the drug. The presence of amino acids, saccharides, glycosides, reducing agents, phenolic substances, and alkaloids in the finished extract was demonstrated by means of colour or precipitation reactions. Thin-layer chromatography was employed to demonstrate gingerols and shogaols. Evaporation residue, ethanol concentration, and the amount of essential oils were determined quantitatively.

[Composite tincture from the tops of the purple coneflower (Echinacea purpurea) and the fruits of the dog rose (Rosa canina): technology of production and evaluation of quality]. / Slozená tinktura z nati trapatky nachové (Echinacea purpurea) a plodu ruze sípkove (Rosa canina): technologie výroby a hodnocení jakosti.

This paper aimed to elaborate the technology of the production of a composite tincture with an immunostimulatory and adaptogenic effect, to select suitable methods of quality evaluation, and perform stability tests. The tops of the purple coneflower (Echinaceae herba) and fruits of the dog rose (Cynosbati fructus) in a ratio of 1:1 were employed to prepare the tincture. The tincture itself was prepared in a ratio of 1:5. The experiment revealed that ethanol 50% was the most suitable extracting agent. The optimal conditions for the obtaining of a quality tincture are formed when the drug is disintegrated into the required degree by grinding, percolation is used for extraction, and the rate of flowing of the extract from the percolator is 0.2 ml/min/100g of the drug. The determination of the dry residue, relative density, ethanol concentration and content of cichoric acid (spectrophotometrically), ascorbic acid (oxidimetrically), and tannins (manganometrically) served to evaluate the quality of prepared extracts. Stability tests (temperature 25+/-2 degrees C, relative humidity 60+/-5%, period of 2 years) have shown that the prepared tincture maintains its quality parameters for the given period.

[Pharmaceutical hydrophilic gels]. / Farmaceutické hydrofilní gely.

From the pharmacopoeial standpoint, gels, together with ointments, creams, pastes, cataplasmata, and medicated plasters, rank among the group of topical semisolid preparations applied to the skin. They are bicoherent systems composed of the internal phase made of a polymer producing a coherent three-dimensional net-like structure, which fixes the liquid vehicle as the external phase. Intermolecular forces bind the molecules of the solvent to a polymeric net, thus decreasing the mobility of these molecules and producing a structured system with increased viscosity. The physical and chemical bonds binding the particles of the internal phase provide a relatively stable structure, which can originate by swelling of solid polymers, or by decreasing the solubility of the polymer in a solution. An important group of gels used in pharmacy are hydrophylic gels, or hydrogels, usually made of hydrophyilc polymers, which under certain conditions and polymer concentration, jellify. Attention of pharmaceutical research now concentrates primarily on hydrophilic gels, as this dosage form seems to be prospective for the development of modern drugs based on systems with prolonged and controlled release of active ingredients.

[Biological availability of ophthalmic preparations. 2. Ophthalmic therapeutic systems]. / Biologická dostupnost ocních léku. 2. Ocní terapeutické systémy.

Ophthalmic therapeutic systems, which rank among the drugs of the second and third generation, make possible prolonged and controlled drug release, or the introduction of the drug direct into the site of action (a specific eye tissue) with minimal distribution into the adjacent tissues. The group mainly consists of solid ophthalmic preparations, in a lesser extent there are systems developed from hydrogels, colloidal carriers, etc. The present review lists both insoluble ophthalmic therapeutic systems and those soluble in water (degradable, erodible). Insoluble systems include membrane-controlled ophthalmic therapeutic systems (e.g. Ocusert), therapeutic eye lenses, eye implants, and other insoluble preparations. In the group of soluble preparations, topical inserts and systems are described, which are introduced into eye tissues as implants or injections.

[Biological availability of ophthalmic drugs. 1. Increasing drug permeability in the cornea]. / Biologická dostupnost ocních léku. 1. Zvýsení prostupnosti léciva rohovkou.

Most eye diseases are treated by topical administration of ophthalmic preparations. Low ophthalmic bioavailability is due to a number of physiological and physicochemical factors. The main obstacle to the penetration of active ingredients to the eye is the layered character of the cornea. Formulation of ophthalmic preparations enabling easier penetration of this biological barrier thus ranks among the most effective ways of improving bioavailability. Penetrability of the cornea can be increased by the following methods: a) adjustment of the actual acidity in such a way that pH of the preparation makes it possible to produce the optimal portion of non-ionized particles; b) incorporation of absorption enhancers (non-ionic tensides, salts of bile acids, some antimicrobial substances, EDTA, cyclodextrins, etc.) into the composition of the preparation, and c) production of prodrugs or ionic pairs.

[Selection of an extraction agent and development of the technology for producing an extract with sedative effects]. / Výber vyluhovadla a vypracování technologie výroby extraktu s uklidnujícím úcinkem.

The drugs Valerinae radix, Crataegi fructus, Leonuri herba and Melissae folium were used to produce a liquid plant extract. The experiment revealed that the extraction with 70% ethanol achieved the highest concentration of extractable active principles. The optimal conditions for obtaining a sedative extract are established when the method of repercolation is used, and in the production itself the batch of the drug is divided into equally large doses and a pre-prepared mixture of plant drugs is extracted. The extract prepared by this manner remains stable for the whole period of storage, i.e., 24 months.

[Two-phase semi-solid hydrophilic systems--hydrocreams]. / Dvoufázové polotuhé hydrofilní systémy--hydrokrémy.

Production of a drug of good quality in the form of a hydrocream presents a wide set of complex problems. Hydrocreams as emulsions of the o/w type form a structured system which consists of at least three phases, the dispersed, crystalline hydrated, and crystalline gel one. The loading operations of manufacturing procedures can negatively affect both the individual components and the complex structure of the hydrocream. Due attention must thus be paid to the formulation study which together with the conditions of manufacture will ensure the production of a drug with required quality indices.