Chlorobutanol

Chlorobutanol, or chlorbutol, is an alcohol-based preservative with no surfactant activity [A32746]. It also elicits sedative-hypnotic and weak local anesthetic actions in addition to antibacterial and antifungal properties. Similar in nature to chloral hydrate, it is formed by the simple nucleophilic addition of chloroform and acetone. As a long-term stabilizer of multi-ingredient preparations, chlorobutanol is normally used at a concentration of 0.5%. At this concentration, it also conserves its antimicrobial activity. Due to the long terminal half-life of 37 days, the use of chlorobutanol as a sedative is limited because of the considerable accumulation which will occur following multiple dosing [A32743]. Chlorobutanol is a common detergent preservative in eye drops and other ophthalmic therapeutic formulations [A32744].