The direct preparation of threo-l,2-glycols without isolation of intermediates from oleic acid, methyl oleate, and oleyl alcohol by oxidation with a hydrogen peroxide (70%)-tmlgstic acid system at pH 0-1 and 45-55C without solvent has now been shown to be an efficient, high-yield reaction.The threo-isomers are formed from intermediate epoxides by in situ hydration with accompanying inversion. Preincorporation of about 2% of the glycol reaction product into oleic acid or methyl oleate speeds up the oxidation reactions markedly and adds to their control and reproducibility. With oleyl alcohol, addition of reaction product is not necessary.Castor and olive oils are also readily oxidized to almost complete elimination of unsaturation, but the products are only 50-60% 1,2-glycols, owing to intra-and intermolecular polyether information. Addition of reaction product is unnecessary with castor oil, but with olive oil the reaction rate is greatly accelerated by incorporation of 2% of reaction product. Preconditioning (5 hr) of the hydrogen peroxide with the tungstie acid permits slightly faster oxidation rates. Emulsions are also rapidly oxidized under appropriate conditions, but these systems are more complicated to prepare and work up than oxidatmn of the substrates directly. Tentative reaction mechanisms are proposed in which an inorganic polyperoxytungstie acid is the effective oxidizing agent and hydroxyl-containing species are intportant interracial or complexing agents between the substrate and oxidant system.
Rates of absorption of atropine after intramuscular injection have been studied by measuring colorimetrically the residual drug in guinea pig muscle. Effects of volume and concentration of the injected solution and the presence of hyaluronidase and polyvinylpyrrolidone on the absorption rates were investigated. Results indicate that, within the range of volumes and concentrations used, for a constant amount of atropine the smaller the volume of injected solution the faster the drug cleared the muscle; solutions of similar volume showed initially faster absorption when a lower concentration of drug was present. Addition of hyaluronidase produced an immediate increase in the clearance rate: four times as much atropine cleared the muscle in the first 35 seconds compared to an untreated solution. Addition of polyvinylpyrrolidone had no appreciable effect.
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