Хлоробутанол

Химические свойства

White or almost white, crystalline powder or colourless crystals, sublimes readily

Использование

Chlorobutanol is used as a preservative and sedative. It has also been shown to exhibit antibacterial properties.

Методы производства

Chlorobutanol is prepared by condensing acetone and chloroform in the presence of solid potassium hydroxide.

Опасность

Action similar to chloral hydrate. Combustible.

Фармацевтические приложения

Chlorobutanol is primarily used in ophthalmic or parenteral dosage forms as an antimicrobial preservative at concentrations up to 0.5% w/v. It is commonly used as an antibacterial agent for epinephrine solutions, posterior pituitary extract solutions, and ophthalmic preparations intended for the treatment of miosis. It is especially useful as an antibacterial agent in nonaqueous formulations. Chlorobutanol is also used as a preservative in cosmetics ; as a plasticizer for cellulose esters and ethers; and has been used therapeutically as a mild sedative and local analgesic in dentistry.

Профиль безопасности

Poison by ingestion. A narcotic. A skin and eye irritant. Mutation data reported. See also CHLORAL HYDRATE, whch acts similarly. Dangerous; can react with oxidizing materials. Combustible when exposed to heat or flame. When heated to decomposition it emits toxic fumes of Cl-. See also PHOSGENE.

Безопасность

Chlorobutanol is widely used as a preservative in a number of pharmaceutical formulations, particularly ophthalmic preparations. Although animal studies have suggested that chlorobutanol may be harmful to the eye, in practice the widespread use of chlorobutanol as a preservative in ophthalmic preparations has been associated with few reports of adverse reactions. A study of the irritation potential of a local anesthetic on the murine cornea indicated significant corneal surface damage in the presence of 0.5% w/v chlorobutanol, which may be related to the preservative’s effective concentration. Reported adverse reactions to chlorobutanol include: cardiovascular effects following intravenous administration of heparin sodium injection preserved with chlorobutanol; neurological effects following administration of a large dose of morphine infusion preserved with chlorobutanol; and hypersensitivity reactions, although these are regarded as rare.
The lethal human dose of chlorobutanol is estimated to be 50–500 mg/kg.
LD₅₀ (dog, oral): 0.24 g/kg
LD₅₀ (mouse, oral): 0.99 g/kg
LD₅₀ (rabbit, oral): 0.21 g/kg

хранилище

Chlorobutanol is volatile and readily sublimes. In aqueous solution, degradation to carbon monoxide, acetone and chloride ion is catalyzed by hydroxide ions. Stability is good at pH 3 but becomes progressively worse with increasing pH. The half-life at pH 7.5 for a chlorobutanol solution stored at 258℃ was determined to be approximately 3 months. In a 0.5% w/v aqueous chlorobutanol solution at room temperature, chlorobutanol is almost saturated and may crystallize out of solution if the temperature is reduced.
Losses of chlorobutanol also occur owing to its volatility, with appreciable amounts being lost during autoclaving; at pH 5 about 30% of chlorobutanol is lost. Porous containers result in losses from solutions, and polyethylene containers result in rapid loss. Losses of chlorobutanol during autoclaving in polyethylene containers may be reduced by pre-autoclaving the containers in a solution of chlorobutanol; the containers should then be used immediately. There is also appreciable loss of chlorobutanol through stoppers in parenteral vials.
The bulk material should be stored in an airtight container at a temperature of 8–158℃.

Несовместимости

Owing to problems associated with sorption, chlorobutanol is incompatible with plastic vials, rubber stoppers, bentonite, magnesium trisilicate, polyethylene, and polyhydroxyethylmethacrylate, which has been used in soft contact lenses. To a lesser extent, carboxymethylcellulose and polysorbate 80 reduce antimicrobial activity by sorption or complex formation.

Регуляторный статус

Included in the FDA Inactive Ingredients Database (IM, IV, and SC injection; inhalations; nasal, otic, ophthalmic, and topical preparations). Labeling must state ‘contains chlorobutanol up to 0.5%.’ Included in nonparenteral and parenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
In the UK, the maximum concentration of chlorobutanol permitted for use in cosmetics, other than foams, is 0.5%. It is not suitable for use in aerosols.