scholarly journals Mosses as biomonitors for radioactivity following the Chernobyl accident

2011 ◽  
Vol 63 (4) ◽  
pp. 1117-1125 ◽  
Author(s):  
Ana Cuculovic ◽  
R. Cuculovic ◽  
Tijana Cvetic-Antic ◽  
D. Veselinovic
Keyword(s):  
Chernobyl Accident ◽  
Transfer Factor ◽  
Half Life ◽  
Biological Half Life

In this work 137Cs and 40K radionuclide concentrations in moss collected at NP Djerdap in the period from 1996 to 2009 are presented. Values of the substrate-moss transfer factor for 137Cs and 40K were calculated. The effective and biological half-life of 137Cs in Homalothecium sericeum moss collected in the period from 1996 to 2008 on the archeological locality of Lepenski Vir was also calculated.

Gastroretentive System of Fluvastatin Sodium by Using Natural Mucilage and Synthetic Polymer

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Umamaheswara G. ◽  
Anudeep D.
Keyword(s):  
Half Life ◽  
Release Kinetics ◽  
Kinetic Studies ◽  
Diffusion Path ◽  
Synthetic Polymer ◽  
In Vitro Dissolution ◽  
Direct Compression ◽  
Drug Content ◽  
Biological Half Life

Fluvastatin sodium is a novel compound used as cholesterol lowering agent which acts through the inhibition of 3- hydroxyl-3- methyl glutaryl- coenzyme A (HMG-Co A) reductase. It has short biological half life (1-3h) in humans required a dosing frequency of 20 to 40mg twice a day. Due to its short variable biological half life it has been developed to a sustained gastroretentive system with a natural and synthetic polymer and to study how far the natural mucilage improves the sustained activity. Floating tablets were prepared by direct compression method using in combination of natural mucilage and synthetic polymer. Prior to the preparation of tablets the physical mixtures were subjected to FT IR studies and pre compression parameters. After preparation of tablets they were subjected to various tests like swollen index, drug content, In vitro dissolution and release kinetics with pcp disso software etc. The tablets prepared by direct compression shown good in thickness, hardness and uniformity in drug content, the prepared tablets floated more than 12h except FS1 and FS2 shows 9 and 11h. Swollen index studies shows with increase in concentration of polymer the swelling increases the diffusion path length by which the drug molecule may have to travel and cause lag time. In vitro results shows that on increasing the amount of hibiscus polymer the sustain activity is increased because of its integrity and forms a thick swollen mass and reduces the erosion property of the HypromelloseK100M, kinetic studies shows that FS 1, FS2, FS3 followed the Korsmeyer peppas model and the rest FS 4, FS 5, FS6 follows the zero order respectively. Based on n value indicating that the drug release followed super case II transport mechanism due to the erosion of the polymer.

Development and Characterization of LBG-PVA Interpenetrating Networks Incorporating Gliclazide for Sustained Release

2020 ◽  
Vol 15 ◽  
Author(s):  
Ashish Katoch ◽  
Manju Nagpal ◽  
Malkiet Kaur ◽  
Manjinder Singh ◽  
Geeta Aggarwal ◽  
...  
Keyword(s):  
Solid State ◽  
Sustained Release ◽  
Half Life ◽  
Solid State Nmr ◽  
Oral Dosage ◽  
Cross Linking ◽  
Interpenetrating Networks ◽  
Dsc Studies ◽  
Biological Half Life ◽  
Percentage Yield

Background: Controlled oral dosage forms have always been preferred for drugs with variable absorption, and short biological half life and frequent dosing. The prime goal with sustained release systems is to maintain uniform therapeutic blood levels for longer periods of time. Interpenetrating networks (IPNs) have been evidenced as uniform sustained release systems. In current study, polyvinyl alcohol (PVA) and locust bean gum (LBG) based IPNs were developed for the oral sustained release drug delivery of gliclazide (shows variable absorption). Method: The IPNs were synthesized by emulsion cross-linking method using glutaraldehyde (GA) as a cross linking agent. Gliclazide is a potential second generation, short-acting sulfonylurea oral hypoglycemic agent is having a short biological half-life (2-4 h), variable absorption and poor oral bioavailability. Various batches of IPNs were formulated by varying LBG: PVA ratio and evaluated for percentage yield, drug entrapment efficiency (DEE), swelling properties and in vitro drug release studies. Further characterizations were done by Fourier Transform Infrared Spectroscopy (FTIR), C13 Solid state NMR, X-Ray diffraction study (XRD), Scanning electron microscopy (SEM), and Differential scanning microscopy (DSC) studies. Results: The percentage yield, drug entrapment and equilibrium swelling was observed to be dependent on PVA-LBG ratio and GA amount. Sustained release of drug was observed in all IPN formulations (approx 59 - 86% in 8 h in various batches) with variable release kinetics. SEM studies revealed the regular structures of IPNs. FTIR, XRD, C13 Solid state NMR and DSC studies proposed that drug was successfully incorporated into the formed IPNs. Conclusion: IPNs of LBG and PVA can be used as a promising carrier with uniform sustained release characteristics.

Biological Half-Life of Cardiolite®

2008 ◽  
Vol 46 (9) ◽  
pp. 522-525 ◽  
Author(s):  
Kenneth Jesse
Keyword(s):  
Half Life ◽  
Biological Half Life

Biological half-life of phenobarbital in human babies

1971 ◽  
Vol 49 (20) ◽  
pp. 1146-1147 ◽  
Author(s):  
Eberhard Heinze ◽  
Hermann G. Kampffmeyer
Keyword(s):  
Half Life ◽  
Biological Half Life

Absorption and Biological Half-Life in Humans of Intrinsic and Extrinsic 54Mn Tracers from Foods of Plant Origin

1991 ◽  
Vol 121 (5) ◽  
pp. 711-717 ◽  
Author(s):  
Phyllis E. Johnson ◽  
Glenn I. Lykken ◽  
Eugene D. Korynta
Keyword(s):  
Half Life ◽  
Plant Origin ◽  
Biological Half Life

scholarly journals Stoffwechsel aromatischer Pflanzeninhaltsstoffe I

1969 ◽  
Vol 24 (2) ◽  
pp. 234-239 ◽  
Author(s):  
Wolfgang Barz
Keyword(s):  
Cicer Arietinum ◽  
Half Life ◽  
Biochanin A ◽  
Pulse Labelling ◽  
Phaseolus Aureus ◽  
Cicer Arietinum L ◽  
Plant Products ◽  
Biological Half Life ◽  
Total Turnover ◽  
Secondary Plant

The turnover of the isoflavones, formononetin and biochanin A, in Cicer arietinum L. and of the isoflavone, daidzein, and the coumestan, coumestrol, in Phaseolus aureus Roxb. has been determined by pulse labelling. The biological half-life of formononetin, daidzein and coumestrol has been found to be approximately 50 hours, while the turnover of biochanin A appeared to be very slow. The excretion of all four plant products through the roots into the medium has been measured. Approximately 3 percent of the total turnover of isoflavones in the plants can be accounted for by excretion into the medium.The results are discussed in view of the concept that secondary plant products may well be subject to further metabolism.

Effect of High Bromide Levels in the Organism on the Biological Half-life of Iodine in the Rat

2001 ◽  
Vol 82 (1-3) ◽  
pp. 125-132 ◽  
Author(s):  
Stanislav Pavelka ◽  
Arnost Babický ◽  
Miloslav Vobecký ◽  
Jaroslav Lener
Keyword(s):  
Half Life ◽  
Biological Half Life

scholarly journals Pharmacokinetics of human chorionic gonadotropin after i.m. administration in goats (Capra hircus)

Reproduction ◽  
2012 ◽  
Vol 144 (1) ◽  
pp. 77-81 ◽  
Author(s):  
M Saleh ◽  
M Shahin ◽  
W Wuttke ◽  
M Gauly ◽  
W Holtz
Keyword(s):  
Rate Constant ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Half Life ◽  
Absorption Rate ◽  
Elimination Rate ◽  
Elimination Rate Constant ◽  
Capra Hircus ◽  
Absorption Rate Constant ◽  
Biological Half Life

The present investigation addresses the pharmacokinetics of human chorionic gonadotropin (hCG), intramuscularly (i.m.) administered to goats. Nine pluriparous does of the Boer goat breed, 2–6 years of age and weighing 45–60 kg, were administered 500 IU hCG (2 ml Chorulon) deep into the thigh musculature 18 h after superovulatory FSH treatment. Blood samples were drawn from the jugular vein at 2 h intervals for the first 24 h, at 6 h intervals until 42 h, and at 12 h intervals until 114 h after administration. After centrifugation, plasma hCG concentrations were determined by electrochemiluminescence immunoassay. Pharmacokinetical parameters were as follows: lag time, 0.4 (s.e.m. 0.1) h; absorption rate constant, 0.34 (s.e.m. 0.002) h; absorption half-life, 2.7 (s.e.m. 0.5) h; elimination rate constant, 0.02 (s.e.m. 0.002) h; biological half-life, 39.4 (s.e.m. 5.1) h; and apparent volume of distribution, 16.9 (s.e.m. 4.3) l. The plasma hCG profile was characterized by an absorption phase of 11.6 (s.e.m. 1.8) h and an elimination phase of 70.0 (s.e.m. 9.8) h, with considerable individual variation in bioavailability and pharmacokinetical parameters. Biological half-life was negatively correlated (P<0.05) with peak concentration (r=−0.76), absorption rate constant (r=−0.78), and elimination rate constant (r=−0.87). The results indicate that after rapid absorption, hCG remains in the circulation for an extended period. This has to be taken into account when assessing the stimulatory response to hCG treatment on an ovarian level.

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