Study of pharmacokinetic of new peptide drug 1-deamino-arginine-vasotocin for hypernatremia correction

Introduction: The pharmacokinetics studies are some of the necessary parts of the drugs preclinical investigations. Pharmacokinetic properties of new peptide drug 1-deamino-arginine-vasotocin (dAVT) in the form of an injection solution for intravenous and intramuscular administration for hypernatremia correction were investigated.

Materials and methods: The study was carried out on male rats and rabbits with a single intravenous administration of the drug in three doses, a single intramuscular administration in one dose and multiple administration to rats in one dose. To determine natriiuretic peptide concentration in blood plasma, tissues, and excretes, assays based on a sodium level change measurement using a biochemical analyzer have been developed and validated. Pharmacokinetic parameters were calculated by the model-independent method of statistical moments.

Results and discussion: The pharmacokinetics of the drug was found to be linear after a single administration of dAVT drug in the dose range 3–10 μg/kg for rats and rabbits. The relative bioavailability of dAVT after intramuscular and intravenous administrations was more than 30%. After a biomarker content change, the active substance was intensively distributed into highly vascularized organs (spleen), the organs that provide metabolism and subsequent excretion (liver and kidneys), whereas it hardly reached moderately and weakly vascularized tissues (muscles, omentum). Less than 10% dAVT was excreted with urine; no dAVT was determined in feces; and repeated administration did not lead to its cumulation.

Conclusion: Pharmacokinetics parameters of new nonapeptide drug 1-deamino-arginine-vasotocin were evaluated after original analytical biomarker approach. The study included all main areas necessary to characterize the original drug pharmacokinetic.

Comparison of biomarker and chromatographic analytical approaches to pharmacokinetic study of sitagliptin

The pharmacokinetic profiling of active compounds is necessary for drug development and application. Approaches to a pharmacokinetic study based on biological markers are alternatives to traditional approaches based on chromatographic methods. The aim of the study was to compare two analytical approaches to pharmacokinetics investigation for an example of sitagliptin in rabbits after one dose oral administration. The method for sitagliptin quantification in rabbit plasma samples based on a correlation between its concentration and dipeptidyl peptidase IV activity was proposed, validated, and applied. The high-performance liquid chromatography (HPLC)-ultraviolet (UV) method was also validated and applied for the same sample analysis. The plasma pharmacokinetics of sitagliptin after oral administration to the rabbits in one dose was characterized after two analytical assays. The close values of the main pharmacokinetic parameters were obtained after two approaches. The nontraditional approach based on correlation of special marker activity and active substance concentration appears to be more sensitive than HPLC-UV. Thus, the sitagliptin concentrations determined by biomarker assay were higher than the lower limit of quantification (LLOQ) for a longer period (more timepoints) than after the HPLC-UV assay. This feature may influence the values of some calculated concentration-dependent (area under the curve [AUC]_0-t , etc.) and time-dependent parameters (mean residence time [MRT], T_1/2 , etc.). The values of T_max obtained by the two approaches were similar and adequate for oral drug administration that confirms the correctness of biomarker selection for pharmacokinetics assessment. The obtained results on the example of sitagliptin confirms that the biomarker approach is adequate and applicable for a pharmacokinetics study. Similar approaches may be effective for individual compounds and complex mixtures when it is difficult or impossible to analyze them traditionally by chromatographic methods.

Natural Deep Eutectic Solvents for the Extraction of Phenyletanes and Phenylpropanoids of Rhodiola rosea L

The extraction of Rhodiola rosea rhizomes using natural deep eutectic solvent (NADES) consisting of lactic acid, glucose, fructose, and water was investigated. A two-level Plackett-Burman design with five variables, followed by the steepest ascent method, was undertaken to determine the optimal extraction conditions. Among the five parameters tested, particle size, extraction modulus, and water content were found to have the highest impact on the extrability of phenyletanes and phenylpropanoids. The concentration of active compounds was analyzed by HPLC. The predicted results showed that the extraction yield of the total phenyletanes and phenylpropanoids (25.62 mg/g) could be obtained under the following conditions: extraction time of 154 min, extraction temperature of 22 °C, extraction modulus of 40, molar water content of 5:1:11 (L-lactic acid:fructose:water, mol/mol), and a particle size of rhizomes of 0.5-1 mm. These predicted values were further verified by validation experiments in predicted conditions. The experimental yields of salidroside, tyrosol, rosavin, rosin, cinnamyl alcohol and total markers (sum of phenyletanes and phenylpropanoids in mg/g) were 11.90 ± 0.02, 0.36 ± 0.02, 12.23 ± 0.21, 1.41 ± 0.01, 0.20 ± 0.01, and 26.10 ± 0.27 mg/g, respectively, which corresponded well with the predicted values from the models.

Pharmacokinetic Study of Bioactive Glycopeptide from Strongylocentrotus droebachiensis After Intranasal Administration to Rats Using Biomarker Approach

A glycopeptide fraction (GPF) from internal organs of green sea urchins (Strongylocentrotus droebachiensis Müller, Strongylocentrotidae) has been reported to be an effective bronchitis treatment. In this study, we evaluated the pharmacokinetic and tissue distribution of GPF, following single and repeated intranasal (i/n) administration over the course of seven days in rats. The method measuring lactate dehydrogenase as biomarker was used to analyse the plasma and tissue concentrations of GPF. GPF appears in the plasma 15 min after single i/n administration (100 µg/kg) and reaches its maximum at 45 min. The area under the curve (AUC)0-24 and Cmax were similar using both i/n and intravenous administration, while mean residence time (MRT) and T1/2 after i/n administration were significantly higher compared with intravenous (i/v) administration. The absolute bioavailability of GPF after i/n administration was 89%. The values of tissue availability (ft) provided evidence about the highest concentration of GPF in the nose mucosa (ft = 34.9), followed by spleen (ft = 4.1), adrenal glands (ft = 3.8), striated muscle (ft = 1.8), kidneys (ft = 0.5), and liver (ft = 0.3). After repeated dose administration, GPF exhibited significantly higher AUC0-24 and MRT, indicating its accumulation in the plasma.

Pharmacokinetic and Tissue Distribution of Fucoidan from Fucus vesiculosus after Oral Administration to Rats

Fucus vesiculosus L., known as bladderwrack, belongs to the brown seaweeds, which are widely distributed throughout northern Russia, Atlantic shores of Europe, the Baltic Sea, Greenland, the Azores, the Canary Islands, and shores of the Pacific Ocean. Fucoidan is a major fucose-rich sulfated polysaccharide found in Fucus (F.) vesiculosus. The pharmacokinetic profiling of active compounds is essential for drug development and approval. The aim of the study was to evaluate the pharmacokinetics and tissue distribution of fucoidan in rats after a single-dose oral administration. Fucoidan was isolated from F. vesiculosus. The method of measuring anti-activated factor X (anti-Xa) activity by amidolytic assay was used to analyze the plasma and tissue concentrations of fucoidan. The tissue distribution of fucoidan after intragastric administration to the rats was characterized, and it exhibited considerable heterogeneity. Fucoidan preferentially accumulates in the kidneys (AUC0–t = 10.74 µg·h/g; Cmax = 1.23 µg/g after 5 h), spleen (AUC0–t = 6.89 µg·h/g; Cmax = 0.78 µg/g after 3 h), and liver (AUC0–t = 3.26 µg·h/g; Cmax = 0.53 µg/g after 2 h) and shows a relatively long absorption time and extended circulation in the blood, with a mean residence time (MRT) = 6.79 h. The outcome of this study provides additional scientific data for traditional use of fucoidan-containing plants and offers tangible support for the continued development of new effective pharmaceuticals using fucoidan.

Pharmacokinetics and Tissue Disposition of Nanosystem-Entrapped Betulin After Endotracheal Administration to Rats

BACKGROUND AND OBJECTIVES

Betulin is a triterpene extracted from the cork layer of the outer bark of Betula spp. It has a wide spectrum of pharmacological activities, including being lung protective; however, its bioavailability is low. To increase its bioavailability, betulin was entrapped in a nanosystem (BN). In this study, we investigated the pharmacokinetics and tissue distribution of nanosystem-entrapped betulin after single dose endotracheal administration to rats.

METHOD

Betulin was nanosystem-entrapped using a solvent exchange technique. The surface morphology and size of the nanosystem were characterized by transmission electron microscopy and dynamic light scattering. The plasma and tissue concentrations of betulin were determined using a validated high-performance liquid chromatography method.

RESULTS

The highest concentration of betulin was found in lungs and liver, and the lowest in the heart. Betulin did not penetrate highly vascularized tissues or tissue with an average degree of vascularization, nor did it cross the blood-brain barrier. Tissue availability in the lungs was 1.3 times higher for BN than for free betulin. Betulin was detected in the bloodstream at 15 min after administration of BN compared with only at 1 h after administration of free betulin. Penetration of betulin in the liver tissue was characterized by a high degree of intensity both for BN and free betulin. Betulin in the heart tissue was detected in much smaller quantities than in the liver.

CONCLUSION

Entrapment of betulin in nanosystem form shows promise as a novel strategy in the treatment of pulmonary diseases.

[Cardioprotective effect of new functional food containing salmon oil with motherwort oil extract]

Combination of fish oil with herbal oil extract can extend functional properties of the products. A new functional food of salmon oil with oil extract of motherwort (8:2) was developed and studied. Qualitative profiling was evidenced about presence of flavonoids and iridoids. Quantification of vitamins A (210±3 IU/g), Е (2.8±0.1 mg/g), D3 (12.2±0.4 IU/g) and PUFA (43.3±0.4%, incl. 9.4±0.1% of omega-3 and 33.9±0.1% of omega-6) was done by modern methods. The developed product was found nontoxic (LD50>15 000 mg/kg b.w., intragastriсally, LD50>3000 mg/kg b.w., intraperitoneal). The 14 days intragastric administration of product to the rats (initial b.w. 200-250 g) at the doses of 2340 and 1170 mg/kg b.w. significantly increased the left ventricular pressure after ischemia comparing with control, and normalized the contraction and relaxation of the left ventricle. Biochemical data confirmed the decrease of aspartate amino transferase and creatine kinase activity in rats treated at all experimental doses. Application of fish oil combination with motherwort oil extract is promising for development of new functional foods with cardio protective properties.

[Comparative analysis of requirements for quality of fish oil for food and medical applications]

Fish oil is reach natural source of vitamins А, Е, D and polyunsaturated fatty acids (PUFA) which are useful for supplementation, prophylaxis and therapy in food industry, medicine and veterinary. The analysis of regulatory documents for the quality of fish oil (based on concentration of main nutrients) leads to conclusion that content of vitamins A and D, and PUFA is controlled in medicinal preparations. With regard to fish oil for food application there is no unified approach. In particularly, content of vitamin D in food supplements with fish oil available on Russian market is not indicated by manufacturer or its concentration varies in 3-10 folds. Because of important biological functions and pharmacological activity, it is very important to have uniform standardization for vitamins and PUFA in fish oil for application in food industry and medicine. Development and unification of analytical methods became special attention for these reasons.

[EXPERIMENTAL STUDY OF PHARMACOKINETICS OF KETOPROFEN NANOSYSTEM FOR INHALATION ADMINISTRATION.]

Pharmacokinetics of ketoprofen nanosystem was studied in outbred rats after single endotracheal administration. Ketoprofen was analyzed in blood serum and tissues by HPLC with UV detection. After endotracheal administration of the nanosystem, ketoprofen rapidly appears in systemic blood flow and its concentration in blood serum reaches maximum after 15 min. The maximum drug concentration in tissues was observed near the site of introduction, namely, in lungs Ketoprofen showed moderate penetration in tissues with high vascularization, and weak penetration in tissues with moderate vascularization. After endotracheal administration of the nanosystem, only small amount of ketoprofen overcomes the blood brain barrier.

Antiallergic effects of pigments isolated from green sea urchin (Strongylocentrotus droebachiensis) shells

This study was undertaken to evaluate possible antiallergic effects of an extract of pigments from green sea urchin (Strongylocentrotus droebachiensis) shells. Effects were studied on animal models - guinea pig ileum contraction, rabbit eyes allergic conjunctivitis, and rabbit local skin irritation. The extract significantly reduced, in a dose-dependent manner, the histamine-induced contractions of the isolated guinea pig ileum with ID50 =1.2 µg/mL (in equivalents of spinochrome B), had an inhibitory effect on the model of ocular allergic inflammation surpassing the reference drug olopatadine, and did not show any irritating effect in rabbits. The extract predominantly contained polyhydroxy-1,4-naphthoquinone which would be responsible for the pharmacological activity. The active compounds of the extract were evaluated in silico with molecular docking. Molecular docking into H1R receptor structures obtained from molecular dynamic simulations showed that all spinochrome derivatives bind to the receptor active site, but spinochrome monomers fit better to it. The results of the present study suggest possibilities for the development of new agents for treating allergic diseases on the base of pigments from sea urchins shells.

Birch bark extract as therapy for chronic hepatitis C--a pilot study

The hepatoprotective effect of birch bark extract (BBE) in patients with chronic hepatitis C (CHC) was studied. Forty-two patients with serologically confirmed chronic hepatitis C were treated for 12 weeks with 160 mg standardized BBE per day. The primary outcome parameter measured was the rate of alanine aminotransferase (ALT) normalization after 12 weeks. Secondary parameters included the course of ALT, aspartate aminotransferase (AST) levels, quantitative HCV RNA levels, subjective symptoms associated with CHC (fatigue, abdominal discomfort, depression, and dyspepsia), safety and compliance. The qualitative-quantitative analysis of BBE was made using high performance liquid chromatography to confirm the presence of 75% betulin and 3.5% betulinic acid. Significant differences in the mean ALT and HCV RNA levels were observed after 12 weeks of treatment. The level of ALT was decreased in 54.0% and normalized (p=0.046). HCV RNA was reduced in 43.2% (p=0.016). After 12 weeks of treatment, reports of fatigue and abdominal discomfort were reduced by 6-fold (p=0.028) and 3-fold (p=0.05), respectively. Dyspepsia was no longer reported (p=0.042) and the effect was significantly different from baseline. Because this study lacks a control group clinical relevance of the data can only be estimated in future by following controlled clinical trials.

[Pharmacokinetics of hopantenic acid upon peroral administration]

A simple, specific and sensitive RP-HPLC method with UV detection for the determination of hopantenic acid in human blood plasma has been developed. The pharmacokinetics of drug pantocalcin upon single peroral administration was investigated on 18 healthy volunteers. The peak of hopantenic acid in blood plasma was achieved at 1.56 h and the elimination half life was 6.68 h. No hopantenic acid in blood plasma is found in 48 h.

Anti-inflammatory activity of a HPLC-fingerprinted aqueous infusion of aerial part of Bidens tripartita L

The anti-inflammatory potential of three doses of an aqueous infusion of aerial parts Bidens tripartita L. against carrageenan-induced acute paw edema in rats was investigated. A phytochemical study and qualitative-quantitative analyses revealed the presence of flavonoids, tannins, polysaccharides, phenols, amino acids, ascorbic acid, organic acids and polyacetylenes. Infusion doses of 20ml/kgbody wt. exhibited significant anti-inflammatory activity in rats, as compared with indomethacin. In addition, the infusion showed analgesic properties in a hot-plate test and antipyretic properties in carrageenan-induced local hyperthermia, both in rats. The effects were dose-dependent. Our results provide evidence for the potential usefulness of B. tripartita infusion in the treatment of inflammatory disorders.

Determination and pharmacokinetic study of taxifolin in rabbit plasma by high-performance liquid chromatography

Taxifolin has been widely used in the treatment of cerebral infarction and sequelae, cerebral thrombus, coronary heart disease and angina pectoris. A reliable sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method with UV detection for the pharmacokinetic study of taxifolin in rabbit plasma after enzymatic hydrolysis was developed and validated for the first time. Taxifolin, with biochanin A as the internal standard, was extracted from plasma samples by liquid/liquid extraction after hydrolysis with beta-glucuronidase and sulfatase. Chromatographic separation was conducted on a Luna C18 column (4.6 mm x 150 mm, 5 microm particle size) and pre-column (2.0 mm, the same sorbent). Two-step linear gradient elution with acetonitrile and 0.03% water solution of trifluoroacetic acid as mobile phase at a flow rate of 1.0 ml/min was used. The UV detector is set at 290 nm. The elution time for taxifolin and biochanin A was approximately 7.9 and 18.3 min, respectively. The calibration curve of taxifolin was linear (r > 0.9997) over the range of 0.03-5.0 microg/ml in rabbit plasma. The limit of detection (LOD) and limit of quantification (LOQ) for taxifolin were 0.03 and 0.11 microg/ml, respectively. The present method was successfully applied for the estimation of the pharmacokinetic parameters of taxifolin following intravenous and oral administration of lipid solution to rabbits. The absolute bioavailability of taxifolin after oral administration of lipid solution was 36%.

[Phytochemical analysis of Hippophae rhamnoides L. fruits from Russian varieties cultivated in Finland and food products containing them]

Results of phytochemical analysis of the berries from six Russian Hippophae rhamnnoides L. varieties (Augustinka, Botanitseskaja, Ljubitelskaja, Vorobjvskaja, Pertsik, Trofimovskaja), cultivated in Finland, are presented. The contents of ascorbic acid (vitamin C), tocopherols (vitamin E), total flavonoid (vitamin P), total carotenoid (vitamin A) and total organic acids were analyzed in unfreezed berries. The same parameters were defined in food products (jelly, sweet sauce and compote) containing fruits of three Hippophae rhamnoides L. varieties (Botanitseskaja, Ljubitelskaja and Trofimovskaja). According to the results, Russian Hippophae rhamnoides L. varieties can be cultivated in South-Finland and different kinds of food products with high quality and concentration of biologically active compounds may be prepared from these berries.

Comparison of high performance TLC and HPLC for separation and quantification of chlorogenic acid in green coffee bean extracts

Two chromatographic methods, high-performance TLC (HPTLC) and HPLC, were developed and used for separation and quantitative determination of chlorogenic acid in green coffee bean extracts. For HPTLC silica gel Kieselgel 60 F 254 plates with ethyl acetate/dichlormethane/formic acid/acetic acid/water (100:25:10:10:11, v/v/v/v/v) as mobile phase were used. Densitometric determination of chlorogenic acid by HPTLC was performed at 330 nm. A gradient RP HPLC method was carried out at 330 nm. All necessary validation tests for both methods were developed for their comparison. There were no statistically significant differences between HPLC and HPTLC for quantitative determination of chlorogenic acid according to the test of equality of the means.

[Light-absorbing and antiradical properties of a product with lutein and zeaxanthin in vitro and kinetics of carotinoids at single oral administration on rats]

Light-absorbing and antiradical properties of the new product on a basis of lutein and zeaxanthin for correction of eye diseases in model system of initiated oxidation of isopropylbenzene were investigated. It is shown, that the product is the effective light-absorbing agent and inhibitor of free-radical oxidation in vitro. In experiments on animals (rat) the pharmacokinetics of the product was investigated at single oral administration. A simple, specific and sensitive RP-HPLC method for the determination of lutein in rat plasma was developed, which was applied to pharmacokinetic investigation in rats after oral administration of lutein at dose 20 mg/kg. It was established, that the peak plasma levels was achieved to 2 hour and the mean elimination half life was 2,4 hours.

Comparison between HPLC and HPTLC densitometry for the determination of icariin fromEpimedium koreanum extracts

Dry extracts of the aerial parts of Epimedium koreanum were quantified by HPLC and high performance TLC (HPTLC). A gradient HPLC method was used for the quantification of the prenylflavone glycoside icariin at 270 nm. A direct HPTLC assay was developed for the determination of icariin at 270 nm. The UV detection of both analytical assays were used to examine the purity of icariin peaks and compared with the standards. The assays provide good accuracy, reproducibility, and selectivity for the quantitative analysis of icariin. The icariin contents of five different dry extracts were compared by HPLC and HPTLC densitometry. The quantitative results of both analytical methods did not show any statistically significant differences between them, although a trend to slightly lower mean values could be found for the HPLC method.

[Biologically active substances in grated cocoa and cocoa butter]

In the article results of comparative analysis of grated cocoa and cocoa butter samples are presented. The investigation was done by modern instrumental methods such as HPLC, GC, UV- VIS-spectroscopy, and also with application of titrimetric and grarimetric methods. In the analyzed samples contents of total phenolics changes in an interval 1,0-3,2%, including monomeric proantocyanidins 0,6-1,35%; pyrroloquinoline quinine (PQQ) 0,34-0,76 microg/g; phenyl ethylamine from 2,79 to 14,97 microg/g, tyramine from 9,56 to 71,68 microg/g, dopamine from 5,3 to 25,85 microg/g; theobromine from 3,3 to 8%, caffeine from 0,49 to 0,70%; among the amino acids at the greatest quantities were presented glutaminic and asparaginic acids, arginin and leucin; three main fatty acids were determined - palmitinic (31+/-2% rel.), oleinic (35+/-2% rel.) and stearinic (35+/-2% rel.); the main phytosterins were sytosterin (up to 192 mg%) and obtusifoliol (up to 198,5 mg%).