| 摘要 |
Poly - 2 - vinylpyridine - N - oxide is prepared by oxidizing poly-2-vinylpyridine of molecular weight about 106 in glacial acetic acid as solvent, with 30% hydrogen peroxide, after which excess hydrogen peroxide is decomposed with palladium and the N-oxide is precipitated by adding sulphuric acid. The wet precipitate is redissolved in water, dialysed, and spray-dried. The resulting polymer has a molecular weight of about 200,000, and 95% of the nitrogen atoms are oxidized to N-oxide groups; it is for use in pharmaceutical compositions (see Divisions A5-A6).ALSO:Solid water-soluble compositions consisting of poly-2-vinyl pyridine-N-oxide and at least one physiologically acceptable salt are prepared by spray-drying an aqueous solution of these components. The aqueous solution preferably contains 2-20% wt./vol. of the N-oxide and at least 10% (by weight of the N-oxide) of the salt. The salts may be one or more of calcium chloride, magnesium chloride, soluble sodium phosphates, sodium bicarbonate or preferably sodium or potassium chloride. The solution may also contain flavouring agents. The solid compositions may be reconstituted with water and administered by injection or inhalation to combat silicosis. |
