http://depa.fquim.unam.mx/amyd/archivero/Modeling-CrusRamirezyVargasPavonyJimenezSolorzano_11276.pdf

Modeling and comparison of dissolution profiles.

Overview of membrane science and technology membrane transport theory membrane and modules concentration polarization reverse osmosis ultrafiltration microfiltration gas separation pervaporation ion exchange membrane processes - electrodialysis carrier facilitated transport medical applications of membranes other membranes processed.

Membrane Technology and Applications

A simple equation for description of solute release I. Fickian and non-fickian release from non-swellable devices in the form of slabs, spheres, cylinders or discs

Modeling of drug release from delivery systems based on hydroxypropyl methylcellulose (HPMC).

Recent advances on chitosan-based micro- and nanoparticles in drug delivery.

ArticlesInvestigation of Human Skin Lipids I

Potassium is rendered nonbitter tasting by combining the same with phytic acid. The final product is useful as a nonbitter tasting potassium supplement for warm-blooded animals deficient in levels of potassium.

Nonbitter tasting potassium product for oral administration to warm-blooded animals and method for preparing same

Results of a kinetics study on the rate of degradation of both laboratory and commercial lots of isoamyl nitrite in sealed ampuls are presented. The reaction appears to be autocatalytic with an effective heat of activation of 20 kcal./mole. Commercial ampuls containing roughly O.33 ml. of the ester explode on developing from 7–12 ml. of by-product gases. Mass spectrometric and gas chromatographic analyses show that these consist largely of nitrogen, nitrous oxide, carbon dioxide, and traces of nitric oxide and carbon monoxide. Results obtained suggest that the first three gases are produced by a secondary reaction between nitric oxide and aldehyde. The liquid products appear to be a mixture consisting of at least twelve components including carboxylic ester, carboxylic acid, isoamyl alcohol, aldehyde, and isoamyl nitrate. The influences of water, acid, alcohol, oxygen, and certain additives on the overall degradative rate are also given.

Kinetics of the degradation of isoamyl nitrite in ampuls I. Nature of reaction products and influence of temperature, oxygen, alcohol, water, and acid on the overall rate

An examination of the usefulness of the spray-drying apparatus in modifying the physical, pharmaceutical, and pharmacological properties of medicinal substances is reported. Spray-drying appeared to be a useful method of modifying the surface area of a powdered substance during its preparation. The addition of wetting and suspending agents modified spray-dried powders, such as precipitated sulfur and mercuric sulfide, so that aggregation effects of the drying procedure were eliminated. The method produced a free-flowing, easily wetted, monodispersible powder. Methylcellulose can be spray-dried to a fine powder; by previously adding a wetting agent, the methylcellulose so produced was found to redissolve rapidly as well as disperse in oil, and with the subsequent addition of water to yield a stable emulsion. Colloidal sulfur was prepared and spray-dried. The dried product was found to be redispersible into its original unaggregated state. Surface areas are reported and preliminary bacteriological data are presented showing the relation of the antiseptic action to the surface area of the various sulfurs.

Studies on pharmaceutical powders and the state of subdivision. iv. the application of spray-drying techniques to pharmaceutical powders

A study of the interaction of sodium polyacrylate, a styrene-maleic anhydride polymer, and a styrene-chloromaleic anhydride polymer with a number of cationic drugs indicated that binding of the drug ions on the dissolved polyelectrolytes occurs, often with concomitant precipitation. It has been shown that Donnan concepts with an auxiliary adsorption equation suffice for the interpretation of the binding behavior of polyacrylate. The styrene polymers, however, exhibit non-Donnan behavior which may be treated exclusively according to the Langmuir theory of adsorption.

Takeru Higuchi

Papers

ArticlesInvestigation of Human Skin Lipids I

Nonbitter tasting potassium product for oral administration to warm-blooded animals and method for preparing same

Kinetics of the degradation of isoamyl nitrite in ampuls I. Nature of reaction products and influence of temperature, oxygen, alcohol, water, and acid on the overall rate

Studies on pharmaceutical powders and the state of subdivision. iv. the application of spray-drying techniques to pharmaceutical powders

Interaction Studies of Cationic Drugs with Anionic Poly Electrolytes II.*: Polyacrylic and Styrene Polymers