Glutaraldehyde is used as a disinfectant and medication. Usually applied as a solution, it is used to sterilize surgical instruments and other areas.
Fixative
Glutaraldehyde is used in biochemistry applications as an amine-reactive homobifunctional crosslinker and fixative prior to SDS-PAGE, staining, or electron microscopy. It kills cells quickly by crosslinking their proteins. It is usually employed alone or mixed with formaldehyde as the first of two fixative processes to stabilize specimens such as bacteria, plant material, and human cells. A second fixative procedure uses osmium tetroxide to crosslink and stabilize cell and organellemembrane lipids. Fixation is usually followed by dehydration of the tissue in ethanol or acetone, followed by embedding in an epoxy resin or acrylic resin. Another application for treatment of proteins with glutaraldehyde is the inactivation of bacterial toxins to generate toxoid vaccines, e.g., the pertussis toxoid component in the Boostrix Tdap vaccine produced by GlaxoSmithKline. In a related application, glutaraldehyde is sometimes employed in the tanning of leather and in embalming.
Wart treatment
As a medication it is used to treat plantar warts. For this purpose, a 10% w/w solution is used. It dries the skin, facilitating physical removal of the wart. Trade names include Diswart Solution and Glutarol.
Safety
Side effects include skin irritation. If exposed to large amounts, nausea, headache, and shortness of breath may occur. Protective equipment is recommended when used, especially in high concentrations. Glutaraldehyde is effective against a range of microorganisms including spores. As a strong sterilant, glutaraldehyde is toxic and a strong irritant. There is no strong evidence of carcinogenic activity. Some occupations that work with this chemical have an increased risk of some cancers.
Mechanism of action
A number of mechanisms have been invoked to explain the biocidal properties of glutaraldehyde. Like many other aldehydes, it reacts with amines and thiol groups, which are common functional groups in proteins. Being bi-function, it is also a potential crosslinker.
Production and reactions
Glutaraldehyde is produced industrially by the oxidation of cyclopentene. Alternatively it can be made by the Diels-Alder reaction of acrolein and vinyl ethers followed by hydrolysis. Like many other dialdehydes, and simple aldehydes, glutaraldehyde converts in aqueous solution to various hydrates that in turn convert to other equilibrating species. Monomeric glutaraldehyde polymerizes by aldol condensation reaction yielding alpha, beta-unsaturated poly-glutaraldehyde. This reaction usually occurs at alkaline pH values.
History and culture
Glutaraldehyde came into medical use in the 1960s. It is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health system. There are a number of other commercial uses such as leather tanning. A glutaraldehyde solution of 0.1% to 1.0% concentration may be used as a biocide for system disinfection and as a preservative for long-term storage. It is a sterilant, killing endospores in addition to many microorganisms and viruses. As a biocide, glutaraldehyde is a component of hydraulic fracturing fluid. It is included in the additive called Alpha 1427. Bacterial growth impairs extraction of oil and gas from these wells. Glutaraldehyde is pumped as a component of the fracturing fluid to inhibit microbial growth.
