Aqueous Viscosity Enhancement through Helical Inclusion Complex Cross-Linking of a Hydrophobically-Modified, Water-Soluble, Cationic Cellulose Ether by Amylose

1997 ◽  
Vol 30 (18) ◽  
pp. 5361-5366 ◽  
Author(s):  
J. V. Gruber ◽  
P. N. Konish
Keyword(s):  
Inclusion Complex ◽  
Water Soluble ◽  
Cross Linking ◽  
Cellulose Ether ◽  
Hydrophobically Modified ◽  
Complex Cross ◽  
Viscosity Enhancement

Solubility Enhancement of the Poorly Water-Soluble Antiulcer Drug Famotidine by Inclusion Complexation

2013 ◽  
Vol 6 (1) ◽  
pp. 1983-1989 ◽  
Author(s):  
Shabnam Ain ◽  
V Gupta ◽  
Babita K ◽  
Q Ain ◽  
J Dahiya
Keyword(s):  
Inclusion Complex ◽  
Dissolution Rate ◽  
Phosphate Buffer ◽  
Physical Mixture ◽  
Water Soluble ◽  
Molar Ratio ◽  
Phase Solubility ◽  
Distilled Water ◽  
Physicochemical Interaction ◽  
Mixture Phase

Aqueous solubility is a critical factor for optimum drug delivery. In the present study, we investigated the potential of drug-cyclodextrin complexation as an approach for improving the solubility and bioavailability of famotidine, an H2-receptor antagonist and acid reducing drug which has poor solubility and bioavailability. Solubility improvement of drug by β-cyclodextrin was done by simple complexation approach using physical, kneading and co-precipitation methods and compared with physical mixture. Phase solubility profile indicated that the solubility of famotidine was significantly increased in presence of β-cyclodextrin and shows a linear graph with β-cyclodextrin indicating formation of inclusion complexes in a 1:1 molar ratio. β-Cyclodextrin-famotidine mixture have maximum stability constant 1477.6 M-1. The inclusion complex ratio 1:1 of kneading mixture was selected based on drug release profile and compared with physical mixture. Further characterization was done by  using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) to identify the physicochemical interaction between drug and carrier and its effect on dissolution. Dissolution rate studies for selected inclusion complex was performed in 0.1 N HCl (pH 1.2), phosphate buffer (pH 7.5) and distilled water (pH 6.8) and compared these to pure drug profile which was found to be 2.34 fold increase in distilled water, 1.83 fold in HCl and 2.01 fold in phosphate buffer (pH 7.5). These results suggest that the kneaded complex of famotidine with β-cyclodextrin as hydrophilic complexation agent can substantially enhance the solubility and dissolution rate. Such complex has promising potential to improve the bioavailability of famotidine.  

Enhancement of the Solubility and Efficacy of Poorly Water-Soluble Drugs by Hydrophobically-Modified Polysaccharide Derivatives

2007 ◽  
Vol 24 (12) ◽  
pp. 2317-2326 ◽  
Author(s):  
Widad Henni-Silhadi ◽  
Michel Deyme ◽  
Marie-Martine Boissonnade ◽  
Martine Appel ◽  
Didier Le Cerf ◽  
...  
Keyword(s):  
Water Soluble ◽  
Poorly Water Soluble Drugs ◽  
Hydrophobically Modified ◽  
Water Soluble Drugs ◽  
Poorly Water Soluble ◽  
Polysaccharide Derivatives

BEHAVIOURAL STUDY OF CYCLODEXTRIN INCLUSION COMPLEX ON ENHANCEMENT OF SOLUBILITY OF ACECLOFENAC

INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (11) ◽  
pp. 19-23
Author(s):  
J Shaikh ◽  
◽  
S. V. Deshmane ◽  
R. N Purohit ◽  
K. R. Biyani
Keyword(s):  
Inclusion Complex ◽  
Solid Dispersion ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Phase Solubility ◽  
Solubility Study ◽  
Cyclodextrin Inclusion ◽  
Poorly Water Soluble ◽  
Cyclodextrin Inclusion Complex

The main objective of the present study was to enhance the solubility and dissolution rate of poorly water soluble aceclofenac using its solid dispersion with β-cyclodextrin. FTIR and DSC study was carried out to find out any incompatibility. The phase solubility of drug was carried out in 1, 2, 5, and 10% of β-cyclodextrin in distilled water. Kneading method and solvent evaporation method was use to prepared solid dispersion of aceclofenac and β-cyclodextrin. Different evaluation tests like solubility study in different solvents, PXRD and in vitro dissolution study of aceclofenac- β-cyclodextrin inclusion complex were carried out. The overall finding indicated that β-cyclodextrin is a desirable water soluble carrier, that helps in increasing solubility of drug. Due to its structural feature, β-cyclodextrin forms a good inclusion complex that decreases contact angle of drug with water molecules by increasing wetting properties. Hence, it can be concluded that, β-cyclodextrin is better water soluble carrier molecule in terms of its compatibility and increasing solubility behavior of poorly water soluble drug aceclofenac.

scholarly journals Improvements of glycol methacrylate. I. Its use as an embedding medium for electron microscopic studies.

1977 ◽  
Vol 25 (3) ◽  
pp. 163-174 ◽  
Author(s):  
R C Spaur ◽  
G C Moriarty
Keyword(s):  
Electron Beam ◽  
Water Soluble ◽  
Cross Linking ◽  
Electron Microscopic ◽  
Glycol Methacrylate ◽  
Ultrastructural Studies ◽  
Tissue Morphology ◽  
Methacrylate Monomer ◽  
Microscopic Studies ◽  
Embedding Medium

The technique for using the water-soluble embedding medium glycol methacrylate has been improved for ultrastructural studies by the simplification of the method of formation of prepolymers used in embedding the tissue, by the addition of a cross-linking agent so that sections are stable in the electron beam, and by improving the softness of the blocks by the addition of a plasticizing agent. The preservation of tissue morphology has been improved by complete dehydration in glycol methacrylate monomer prior to infiltration with the prepolymer. Preservations of tissue morphology is further enhanced by complete dehydration in ethanols and embedding in the improved glycol methacrylate medium.

Flow of Hydrophobically Modified Water-Soluble-Polymer Solutions in Porous Media: New Experimental Insights in the Diluted Regime

SPE Journal ◽  
2010 ◽  
Vol 16 (01) ◽  
pp. 43-54 ◽  
Author(s):  
Guillaume Dupuis ◽  
David Rousseau ◽  
René Tabary ◽  
Bruno Grassl
Keyword(s):  
Oil Recovery ◽  
Polymer Concentration ◽  
Adsorbed Layer ◽  
Water Soluble ◽  
Water Soluble Polymer ◽  
Improved Oil Recovery ◽  
Water Soluble Polymers ◽  
Resistance Factors ◽  
Soluble Polymers ◽  
Hydrophobically Modified

Summary The specific molecular structure of hydrophobically modified water-soluble polymers (HMWSPs), also called hydrophobically associative polymers, gives them interesting thickening and surface-adsorption abilities compared with classical water-soluble polymers (WSPs), which could be useful in polymer-flooding and well-treatment operations. However, their strong adsorption obviously can impair their injectivity, and, conversely, the shear sensitivity of their gels can be detrimental to well treatments. Determining for which improved-oil-recovery (IOR) application HMWSPs are best suited, therefore, remains difficult. The aim of this work is to bring new insight regarding the interaction mechanisms between HMWSPs and rock matrix and the consequences concerning their propagation in reservoirs. A consistent set of HMWSPs with sulfonated polyacrylamide backbones and alkyl hydrophobic side chains together with an equivalent WSP was synthesized and fully characterized. HMWSP and WSP solutions were then injected in model granular packs. As expected, with HMWSPs, high resistance factors (or mobility reductions, Rm) were observed. Yet, within the limit of the injected volumes, the effluent showed the same viscosity and polymer concentration as the injected solutions. A first significant outcome concerns the specificities of the Rm curves during HMWSP injections. Rm increases took place in two steps. The first corresponded to the propagation of the viscous front, as observed with WSP, whereas the second was markedly delayed, occurring several pore volumes (PV) after the breakthrough. This result is not compatible with the classical picture of multilayer adsorption of HMWSPs but suggests that injectivity is controlled solely by the adsorption of minor polymeric species. This hypothesis was confirmed by reinjecting the collected effluents into fresh cores; no second-step Rm increases were observed. Brine injections in HMWSP-treated cores revealed high residual resistance factors (or irreversible permeability reductions, Rk), which can be attributed to the presence of thick polymer-adsorbed layers on the pore surface. Nevertheless, Rk values strongly decreased when increasing the brine-flow rate. This second significant outcome shows that the adsorbed-layer thickness is shear-controlled. These new results should lead to proposing new adapted filtration and injection procedures for HMWSPs, aimed, in particular, at improving their injectivity.

Water-soluble loratadine inclusion complex: Analytical control of the preparation by microwave irradiation

2008 ◽  
Vol 48 (3) ◽  
pp. 1020-1023 ◽  
Author(s):  
Á. Nacsa ◽  
R. Ambrus ◽  
O. Berkesi ◽  
P. Szabó-Révész ◽  
Z. Aigner
Keyword(s):  
Microwave Irradiation ◽  
Inclusion Complex ◽  
Water Soluble ◽  
Analytical Control

Chitosan Cross-Linking with a Water-Soluble, Blocked Diisocyanate. 2. Solvates and Hydrogels

2003 ◽  
Vol 4 (5) ◽  
pp. 1357-1361 ◽  
Author(s):  
Eric R. Welsh ◽  
Ronald R. Price
Keyword(s):  
Water Soluble ◽  
Cross Linking
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