scholarly journals Gellan gum-O,O ′-bis(2-aminopropyl)-polyethylene glycol hydrogel for controlled fertilizer release

2017 ◽  
Vol 135 (2) ◽  
pp. 45636 ◽  
Author(s):  
R. C. Sabadini ◽  
M. M. Silva ◽  
A. Pawlicka ◽  
J. Kanicki
2014 ◽  
Vol 21 (5) ◽  
Author(s):  
Settimio Pacelli ◽  
Patrizia Paolicelli ◽  
Federico Pepi ◽  
Stefania Garzoli ◽  
Alessandro Polini ◽  
...  

Cellulose ◽  
2015 ◽  
Vol 22 (3) ◽  
pp. 2045-2054 ◽  
Author(s):  
Rodrigo C. Sabadini ◽  
Virginia C. A. Martins ◽  
Agnieszka Pawlicka

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1699 ◽  
Author(s):  
Nair ◽  
Shah ◽  
Aljaeid ◽  
Al-Dhubiab ◽  
Jacob

Poor solubility and appreciable first-pass metabolism have limited the oral bioavailability of nebivolol. The objective of the current investigation was to design, formulate, and optimize a hydrogel-based transdermal system for nebivolol using factorial design and compare its pharmacokinetics with oral suspension. Hydrogel formulations (F1–F8) were prepared by varying the amounts of gellan gum, carbopol, and polyethylene glycol. A 23 full factorial design was used to assess the effect of independent variables such as gellan gum, carbopol, and polyethylene glycol 400 on dependent variables like viscosity, in vitro release, and ex vivo permeation after 2 h at two levels. Optimized gel (F7), containing nebivolol hydrochloride (75 mg), gellan gum (300 mg), carbopol (150 mg), polyethylene glycol 400 (20 µl), tween 80 (1 ml), ethanol (10 ml), and water (up to 30 ml) was selected and evaluated in albino rats. The physicochemical properties of F7 (pH: 7.1 ± 0.15, viscosity: 8943 ± 116 centipoise, drug content: 98.81% ± 2.16%) seem ideal for transdermal application. It was noticed that the concentration of carbopol has a more significant role than gellan gum in gel viscosity. A biphasic release pattern was exhibited by gels, and the release rate was mainly influenced by the concentration of gellan gum. Greater transdermal flux (30.86 ± 4.08 µg/cm2/h) was observed in F7 as compared with other prepared gels. Noticeable enhancement in AUC0-α value (986.52 ± 382.63 ng.h/ml; p < 0.01) of transdermal therapy (~2-fold higher compared with oral administration) established the potential of F7 to improve the rate and extent of nebivolol delivery. The overall results demonstrated here signify that F7 could be a feasible alternative to oral therapy of nebivolol.


Author(s):  
Kuixiong Gao ◽  
Randal E. Morris ◽  
Bruce F. Giffin ◽  
Robert R. Cardell

Several enzymes are involved in the regulation of anabolic and catabolic pathways of carbohydrate metabolism in liver parenchymal cells. The lobular distribution of glycogen synthase (GS), phosphoenolpyruvate carboxykinase (PEPCK) and glycogen phosphorylase (GP) was studied by immunocytochemistry using cryosections of normal fed and fasted rat liver. Since sections of tissue embedded in polyethylene glycol (PEG) show good morphological preservation and increased detectability for immunocytochemical localization of antigenic sites, and semithin sections of Visio-Bond (VB) embedded tissue provide higher resolution of cellular structure, we applied these techniques and immunogold-silver stain (IGSS) for a more accurate localization of hepatic carbohydrate metabolic enzymes.


Author(s):  
Dai Dalin ◽  
Guo Jianmin

Lipid cytochemistry has not yet advanced far at the EM level. A major problem has been the loss of lipid during dehydration and embedding. Although the adoption of glutaraldehyde and osmium tetroxide accelerate the chemical reaction of lipid and osmium tetroxide can react on the double bouds of unsaturated lipid to from the osmium black, osmium tetroxide can be reduced in saturated lipid and subsequently some of unsaturated lipid are lost during dehydration. In order to reduce the loss of lipid by traditional method, some researchers adopted a few new methods, such as the change of embedding procedure and the adoption of new embedding media, to solve the problem. In a sense, these new methods are effective. They, however, usually require a long period of preparation. In this paper, we do research on the fiora nectary strucure of lauraceae by the rapid-embedding method wwith PEG under electron microscope and attempt to find a better method to solve the problem mentioned above.


1992 ◽  
Vol 85 (2) ◽  
pp. 345-351 ◽  
Author(s):  
Gokarna B. Gharti-Chhetri ◽  
Wichai Cherdshewasart ◽  
Jocelyne Dewulf ◽  
Michel Jacobs ◽  
loan Negrutiu

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