Oral composition

Oral care composition comprising a polymer obtainable by copolymerising a mixture of comonomers, from 5 to 95 mol % of the mixture of comonomers is constituted by a como no mer having the formula (I): (I) in which R is hydrogen or a methyl group, L is a divalent organic linking group incorporating a benzylor a carboxyl functionality, n is an integer of from 1 to 4 and Y is an amine, quaternized amine or quaternary ammonium group; and in which the balance of the mixture of co monomers is constituted by neutral and/or anionic comonomers; said composition being in the form of anyone of a toothpaste, gel, foam, chewing gum, deformable strip or mouthwash and being suitable for use in the oral cavity

Phase Behavior of Polyelectrolyte Block Copolymers in Mixed Solvents

We have studied the phase behavior of the poly(n-butyl acrylate)-b-poly(acrylic acid) block copolymer in a mixture of two miscible solvents, water and tetrahydrofuran (THF). The techniques used to examine the different polymers, structures and phases formed in mixed solvents were static and dynamic light scattering, small-angle neutron scattering, nuclear magnetic resonance and fluorescence microscopy. By lowering the water/THF mixing ratio X, the sequence unimers, micron-sized droplets, polymeric micelles was observed. The transition between unimers and the micron-sized droplets occurred at X = 0.75, whereas the microstructuration into core-shell polymeric micelles was effective below X = 0.4. At intermediate mixing ratios, a coexistence between the micron-sized droplets and the polymeric micelles was observed. Combining the different aforementioned techniques, it was concluded that the droplet dispersion resulted from a solvent partitioning that was induced by the hydrophobic blocks. Comparison of poly(n-butyl acrylate) homopolymers and poly(n-butyl acrylate)-b-poly(acrylic acid) block copolymers suggested that the droplets were rich in THF and concentrated in copolymers and that they were stabilized by the hydrophilic poly(acrylic acid) moieties.Comment: 11 pages, 12 figures, to appear in Macromolecule

Adverse effects of the antimalaria drug, mefloquine: due to primary liver damage with secondary thyroid involvement?

BACKGROUND: Mefloquine is a clinically important antimalaria drug, which is often not well tolerated. We critically reviewed 516 published case reports of mefloquine adverse effects, to clarify the phenomenology of the harms associated with mefloquine, and to make recommendations for safer prescribing. PRESENTATION: We postulate that many of the adverse effects of mefloquine are a post-hepatic syndrome caused by primary liver damage. In some users we believe that symptomatic thyroid disturbance occurs, either independently or as a secondary consequence of the hepatocellular injury. The mefloquine syndrome presents in a variety of ways including headache, gastrointestinal disturbances, nervousness, fatigue, disorders of sleep, mood, memory and concentration, and occasionally frank psychosis. Previous liver or thyroid disease, and concurrent insults to the liver (such as from alcohol, dehydration, an oral contraceptive pill, recreational drugs, and other liver-damaging drugs) may be related to the development of severe or prolonged adverse reactions to mefloquine. IMPLICATIONS: We believe that people with active liver or thyroid disease should not take mefloquine, whereas those with fully resolved neuropsychiatric illness may do so safely. Mefloquine users should avoid alcohol, recreational drugs, hormonal contraception and co-medications known to cause liver damage or thyroid damage. With these caveats, we believe that mefloquine may be safely prescribed in pregnancy, and also to occupational groups who carry out safety-critical tasks. TESTING: Mefloquine's adverse effects need to be investigated through a multicentre cohort study, with small controlled studies testing specific elements of the hypothesis

Oral composition

Oral care composition comprising a polymer obtainable by copolymerising a mixture of comonomers, from 5 to 95 mol % of the mixture of comonomers is constituted by a como no mer having the formula (I): (I) in which R is hydrogen or a methyl group, L is a divalent organic linking group incorporating a benzylor a carboxyl functionality, n is an integer of from 1 to 4 and Y is an amine, quaternized amine or quaternary ammonium group; and in which the balance of the mixture of co monomers is constituted by neutral and/or anionic comonomers; said composition being in the form of anyone of a toothpaste, gel, foam, chewing gum, deformable strip or mouthwash and being suitable for use in the oral cavity

Oral composition

Oral care composition comprising a polymer obtainable by copolymerising a mixture of comonomers, from 5 to 95 mol % of the mixture of comonomers is constituted by a como no mer having the formula (I): (I) in which R is hydrogen or a methyl group, L is a divalent organic linking group incorporating a benzylor a carboxyl functionality, n is an integer of from 1 to 4 and Y is an amine, quaternized amine or quaternary ammonium group; and in which the balance of the mixture of co monomers is constituted by neutral and/or anionic comonomers; said composition being in the form of anyone of a toothpaste, gel, foam, chewing gum, deformable strip or mouthwash and being suitable for use in the oral cavity

Dithiocarbamates as universal reversible addition-fragmentation chain transfer agents

International audienceControl of the radical polymerization of acrylates, styrene and vinyl acetate has been achieved by using novel dithiocarbamates as reversible addition-fragmentation chain transfer agents. The key parameter for the control with N,N-disubstituted (A) or cyclic (B) dithiocarbamates was found to be the conjugation of the lone pair of electrons of the nitrogen atom with carbonyl or aromatic groups. © WILEY-VCH Verlag GmbH 2000