Biomaterial Database

Studies of the internal flow process in polymers by 1H NMR microscopy at 500 MHz. 1998

B Madhu, and J Hjärtstam, and B Soussi

Bioenergetics Group, Wallenberg Laboratory and Lundberg Laboratory for Bioanalysis, University of Göteborg, S-413 45, Göteborg, Sweden.

Nuclear Magnetic Resonance (NMR) microscopy was used to study the dynamics and diffusion of the internal water flow in erodible Hydroxypropylmethylcellulose (HPMC) and Polyvinylalcohol (PVA) polymers of pharmaceutical interest. Polymers in the form of tablets were hydrated at 37 degreesC continuously and monitored at regular intervals with a 500 MHz NMR microscope. The diffusion and spin-spin relaxation time (T2)-weighted images revealed that the gel layer was strongly attached to the core of the tablet in both HPMC and PVA polymers. Spatial distribution of self diffusion coefficients (SDCs) and T2 of the hydrating polymers were calculated from NMR microscopic images.

UI	MeSH Term	Description	Entries
D008747	Methylcellulose	Methylester of cellulose. Methylcellulose is used as an emulsifying and suspending agent in cosmetics, pharmaceutics and the chemical industry. It is used therapeutically as a bulk laxative.	BFL,Celevac,Cellothyl,Cellulone,Citrucel,Cologel,Dacryolarmes,Methocel,Methyl Cellulose,Muciplasma,Cellulose, Methyl
D008853	Microscopy	The use of instrumentation and techniques for visualizing material and details that cannot be seen by the unaided eye. It is usually done by enlarging images, transmitted by light or electron beams, with optical or magnetic lenses that magnify the entire image field. With scanning microscopy, images are generated by collecting output from the specimen in a point-by-point fashion, on a magnified scale, as it is scanned by a narrow beam of light or electrons, a laser, a conductive probe, or a topographical probe.	Compound Microscopy,Hand-Held Microscopy,Light Microscopy,Optical Microscopy,Simple Microscopy,Hand Held Microscopy,Microscopy, Compound,Microscopy, Hand-Held,Microscopy, Light,Microscopy, Optical,Microscopy, Simple
D011142	Polyvinyl Alcohol	A polymer prepared from polyvinyl acetates by replacement of the acetate groups with hydroxyl groups. It is used as a pharmaceutic aid and ophthalmic lubricant as well as in the manufacture of surface coatings artificial sponges, cosmetics, and other products.	Liquifilm Tears,Polyviol,Alcohol, Polyvinyl,Tears, Liquifilm
D004058	Diffusion	The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.	Diffusions
D013607	Tablets	Solid dosage forms, of varying weight, size, and shape, which may be molded or compressed, and which contain a medicinal substance in pure or diluted form. (Dorland, 28th ed)	Tablet
D013816	Thermodynamics	A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)	Thermodynamic
D019906	Nuclear Magnetic Resonance, Biomolecular	NMR spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope.	Biomolecular Nuclear Magnetic Resonance,Heteronuclear Nuclear Magnetic Resonance,NMR Spectroscopy, Protein,NMR, Biomolecular,NMR, Heteronuclear,NMR, Multinuclear,Nuclear Magnetic Resonance, Heteronuclear,Protein NMR Spectroscopy,Biomolecular NMR,Heteronuclear NMR,Multinuclear NMR,NMR Spectroscopies, Protein,Protein NMR Spectroscopies,Spectroscopies, Protein NMR,Spectroscopy, Protein NMR
D065347	Hypromellose Derivatives	Polymeric compounds that contain repeating units of hydroxypropyl methylcellulose. The properties of hypromellose polymers can vary greatly and are defined by their molecular weight, the percentage of hydroxyl groups, the percentage of hydroxypropyl groups, and viscosity measurements. They are found a broad variety of commercial products such as FOOD ADDITIVES; EXCIPIENTS; and LUBRICANTS.	HPMC 2910,HPMC-K-100 M,Hydroxypropyl Methylcellulose,Hydroxypropylmethylcellulose,Hypromellose,K-8515,K8515,MHPC Polymer,Methocel E,Methoxyhydroxypropylcellulose,Methyl Hydroxypropyl Cellulose,Methyl-hydroxypropyl-cellulose,Derivative, Hypromellose,Derivatives, Hypromellose,HPMC K 100 M,HPMCK100 M,Hypromellose Derivative,K 8515