Effect of pH and Ionic Strength on the Distribution Coefficients of Alkaline Earth Metals and Nickel with Chelating Ion-Exchange Resins.

AbstractFunctional groups which form chelate compounds with metal ions have long been of analytical usefulness. Such compounds have served as titrants, precipitating reagents, extractants, and as ionogenic groups on ion exchange resins. These ion exchange resins often have high distribution coefficients which enable the quantitative extraction of metal ions from solution in a single batch treatment with the resin. This report describes the application of chelating resins to sampling and determination of certain trace metals using x-ray fluorescence. Two commercial resins will be discussed. Chelex- 100 (Bio Rad) is a resin containing iminodiacetic acid functional groups and has chelation chemistry quite similar to EDTA. NMRR (Srafion) is a resin containing a functional site selective for gold, platinum metals, mercuric ions and methyl mercury.

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Embedding Procedure for Water Swollen Samples

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006951x ◽

1970 ◽

Vol 28 ◽

pp. 504-505

Author(s):

Ann M. Thomas ◽

Virginia Shemeley

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Ion Exchange ◽

Structural Changes ◽

Cross Linking ◽

Ion Exchange Resins ◽

Transmission Electron ◽

First Pass ◽

Exchange Resins

Those samples which swell rapidly when exposed to water are, at best, difficult to section for transmission electron microscopy. Some materials literally burst out of the embedding block with the first pass by the knife, and even the most rapid cutting cycle produces sections of limited value. Many ion exchange resins swell in water; some undergo irreversible structural changes when dried. We developed our embedding procedure to handle this type of sample, but it should be applicable to many materials that present similar sectioning difficulties.The purpose of our embedding procedure is to build up a cross-linking network throughout the sample, while it is in a water swollen state. Our procedure was suggested to us by the work of Rosenberg, where he mentioned the formation of a tridimensional structure by the polymerization of the GMA biproduct, triglycol dimethacrylate.

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Applications of Ion Exchange Resin in Oral Drug Delivery Systems

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v7i03.9556 ◽

2017 ◽

Vol 7 (03) ◽

Author(s):

Kathpalia Harsha ◽

Das Sukanya

Keyword(s):

Drug Delivery ◽

Ion Exchange ◽

Drug Delivery Systems ◽

Oral Drug Delivery ◽

Physical Stability ◽

Delivery Systems ◽

Oral Drug ◽

Ion Exchange Resins ◽

Exchange Resins ◽

Oral Drug Delivery Systems

Ion Exchange Resins (IER) are insoluble polymers having styrene divinylbenzene copolymer backbone that contain acidic or basic functional groups and have the ability to exchange counter ions with the surrounding aqueous solutions. From the past many years they have been widely used for purification and softening of water and in chromatographic columns, however recently their use in pharmaceutical industry has gained considerable importance. Due to the physical stability and inert nature of the resins, they can be used as a versatile vehicle to design several modified release dosage forms The ionizable drug is complexed with the resin owing to the property of ion exchange. This resin complex dissociatesin vivo to release the drug. Based on the dissociation strength of the drug from the drug resin complex, various release patterns can be achieved. Many formulation glitches can be circumvented using ion exchange resins such as bitter taste and deliquescence. These resins also aid in enhancing disintegrationand stability of formulation. This review focuses on different types of ion exchange resins, their preparation methods, chemistry, properties, incompatibilities and their application in various oral drug delivery systems as well as highlighting their use as therapeutic agents.

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