EVALUATION OF ACRYLATES/C10-30 ALKYL ACRYLATE CROSS- POLYMER MIXTURE EFFECTIVENESS ON O/W TYPE EMULSION FORMULATION.

Acrylates/C1O-30 alkyl acrylate cross-polymer mixtures were used in order to prepare stable and oil-in-water (o/w) pharmaceutical emulsions of organic oils. The resulting o/w pre-emulsions, prepared with different alkyl acrylate cross-polymers were unequally stable. We observed a synergistic effect when a polymer mixture was used and-the resulting pre-emulsions were more stable for significant duration. The observed effect is confirmed by, statistical analysis, the feature is remarkably important when we look for more stable pharmaceutical emulsions formed with less additives.

The development and in vitro evaluation of herbal pellets coated with Eudragit FS 30.

The objective of this study was to prepare pellets of thyme (Thymus vulgaris L.), stinging nettle (Urtica dioica L.) and sage (Salvia officinalis L.) dry extracts by extrusion-spheronization technique to improve technological properties and investigate dissolution profiles of pellets covered different levels of pH-sensitive polymer Eudragit® FS. Optimal sample of pellets were prepared using microcrystalline cellulose and lactose as excipients and demonstrated excellent technological quality properties such as Hausner ratio (1.07 ± 0.11) and compressibility index (6.73 ± 0.94%) value, spericity (0.87 ± 0.001) and friability (0.22 ± 0.08 N). Pellets were coated by 10-35% (w/w) of Eudragit® FS. Dissolution studies showed that less than 20% of coating could not prevent dissolution of phenols in pH 1.2, 20% Eudragit® FS coating is enough to prevent herbal extract against dissolution in the stomach. There were observed no statistical significant differences between 20% and 25% or higher amount of coating polymer to a dissolution of phenols in low pH.

The development of Eudragit® NM-based controlled-release matrix tablets.

UNLABELLED: Eudragit® NM was investigated as a matrix former in combination with microcrystalline cellulose as an insoluble filler for preparing controlled-release tablets containing model drugs with different solubility. MATERIAL AND METHODS: Three sets of matrix tablets differing in the drug-to-filler ratio (1:1, 2:1, and 4:1) and polymer amount with diltiazem hydrochloride (freely soluble) or caffeine (sparingly soluble) were prepared. Samples were evaluated by the dissolution test at pH 6.8 corresponding to the upper part of the small intestine; the selected samples were tested at a changing pH level to better simulate in vivo conditions. RESULTS: The prepared matrix tablets fulfilled all the requirements of the European Pharmacopoeia. Tablets with Eudragit® NM showed excellent mechanical characteristics. In vitro studies showed that the set 1:1 was the most suitable for the sustained release of a freely soluble drug concerning the burst effect and the total drug amount released within 12 hours. The significant effect of the drug-to-filler ratio and polymer amount on the dissolution profile was confirmed by similarity factor analysis. A faster drug release was observed during the dissolution test within changing pH levels because of the pH-dependent solubility of diltiazem. A prolonged release of the sparingly soluble drug was not achieved, and a trend for fast disintegration was observed. CONCLUSIONS: The combination of Eudragit®NM with microcrystalline cellulose as an insoluble filler seems to be suitable only for freely soluble drugs, when the amount of the drug and the filler is similar.

Comparison of long-term stability of parenteral all-in-one admixtures containing new lipid emulsions prepared under hospital pharmacy conditions.

UNLABELLED: All-in-one (AIO) admixtures for parenteral nutrition are common in hospital pharmacy practices. They are extemporaneously prepared and should be stable during preparation, storage, and administration. Lipid emulsion is a clinically important and very susceptible component of instability. The objective of study was to evaluate the long-term stability of AIO admixtures containing modern lipid emulsions. MATERIAL AND METHODS: AIO admixtures with two different emulsions (SMOFlipid and Lipoplus) containing the same amount of glucose and complex amino acid solution, and variable amounts of ions were prepared. Samples were evaluated at 2, 5, 8 and 30 days after preparation. The main indicator of AIO system stability was the amount of lipid globules greater than 5 µm in diameter, which is limited by pharmacopoeia. Optical microscopy was used for particle size measurement. RESULTS: All prepared AIO admixtures remained stable during observation. The counts of overlimit lipid particles were within pharmacopeial limit nevertheless tended to increase in time. After 30-day storage, their value was influenced mainly by concentration of calcium ions, which at lower concentrations had a greater impact on SMOFlipid-based admixtures, whereas at the highest concentration on Lipoplus-based admixtures. The concentration of ions and osmolarity remained without changes; pH of admixtures slightly decreased. CONCLUSIONS: Both lipid emulsions were found to be suitable for preparation AIO admixtures with different concentrations of electrolytes. The formulations were stable even if contained high concentrations of divalent ions. The comparison of emulsions revealed the superiority of Lipoplus - electrolyte concentrations and duration of storage had a greater impact on admixtures with SMOFlipid.

The effect of Ginkgo biloba extract on mitochondrial oxidative phosphorylation in the normal and ischemic rat heart.

Free radical-induced myocardial damage and impairment of vascular endothelium-dependent relaxation are amongst the most important mechanisms responsible for ischemic heart injury. Ginkgo biloba leaf extract (GE) has been reported to improve blood circulation in the brain and have a beneficial impact on the cardiovascular system but its cardioprotective effects have not been elucidated yet. Therefore, this study investigated the influence of GE in 70% ethanol (1:5) administered orally to rats on the functions of isolated heart mitochondria under normal and ischemic conditions. Wistar rats were given GE or ethanol (solvent control) at a dosage of 0.32 mL/kg in drinking water for 10 and 18 days, while the control animals received untreated drinking water. Mitochondrial respiration rates were determined oxygraphically. Pyruvate and malate, succinate or palmitoyl-L-carnitine and malate were used as substrates. The GE treatment partially uncoupled mitochondrial oxidation from phosphorylation, reduced the generation of free radicals in the mitochondria, diminished the ischemia-induced V3 decrease and the degree of respiration stimulation by exogenous cytochrome c. Thus, these results indicate that GE exerts cardioprotective effects reducing ischemia-caused impairment of the functions of heart mitochondria.

Free radical-scavenging activities of Crataegus monogyna extracts.

UNLABELLED: The aim of this study was to investigate antiradical activity of aqueous and ethanolic hawthorn fruit extracts, their flavonoids, and flavonoid combinations. MATERIAL AND METHODS: Total amount of phenolic compounds and the constituents of flavonoids were determined using a high-performance liquid chromatography. The antioxidant activity of Crataegus monogyna extracts and flavonoids (chlorogenic acid, hyperoside, rutin, quercetin, vitexin-2O-rhamnoside, epicatechin, catechin, and procyanidin B(2)) quantitatively was determined using the method of spectrophotometry (diphenyl-1-picrylhydrazyl (DPPH.) radical scavenging assay and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid)(ABTS.+) radical cation decolorization assay). The level of tyrosine nitration inhibition was determined using a high-performance liquid chromatography. RESULTS: Ethanolic hawthorn fruit extract contained 182+/-4 mg/100 mL phenolic compounds, i.e. threefold more, as compared to aqueous extract. The antioxidant activity according to DPPH. reduction in the ethanolic extracts was higher 2.3 times (P<0.05). The ABTS.+ technique showed that the effect of ethanolic extracts was by 2.5 times stronger than that of aqueous extracts. Tyrosine nitration inhibition test showed that the effect of ethanolic extracts was by 1.4 times stronger than that of aqueous extracts. The investigation of the antiradical activity of the active constituents in aqueous and ethanolic extracts revealed that epicatechin and catechin contribute to radical-scavenging properties more than other components. Procyanidin B(2) only insignificantly influenced the antiradical activity of the extracts. CONCLUSION: Both aqueous and ethanolic hawthorn extracts had antiradical activity, but ethanolic extract had stronger free radical-scavenging properties, compared to the aqueous extract. The antioxidant activity of the studied preparations was mostly conditioned by epicatechin and catechin. The individual constituents of both extracts had weaker free radical-scavenging properties than the combination of these substances did.

The search for the criteria in reforming health care: evaluation of the spatial accessibility of primary healthcare service.

This article analyzes the spatial accessibility of primary healthcare services, i.e. the population's possibilities to receive healthcare services within an acceptable period of time in healthcare institutions situated in a certain territorial-administrative unit--the municipality. The aim of the study was to develop the technique for the quantitative evaluation of the spatial accessibility of primary healthcare services in different territories. The object of the study was the network of primary healthcare institutions and their subdivisions in the municipalities of Klaipeda, Taurage, and Vilnius districts. The methods of the study were geometrical modeling and applied graphics used for the quantitative determination of the ratios between the total zone area of the accessible primary healthcare institutions and the area of the respective municipal territory. The result of the study was the developed and proposed technique allowing for the evaluation of the spatial accessibility of primary healthcare institutions. The proposed technique of the evaluation of the spatial accessibility of primary healthcare services may be valuable in solving the problems of the development of primary healthcare institutions primarily in the rural regions of Lithuania. The quantitative expression of the evaluation could be used in decision-making related to investments into the development of the primary healthcare institution network in different administrational units of the country. The method of geometrical modeling involving the application of digital graphics may create preconditions for the creation of the geographical information system of the primary healthcare institution network in Lithuania.