|Trade names||Colace, Ex-Lax Stool Softener, others|
|By mouth or rectally|
|Drug class||Stool softener|
|Onset of action||12 hrs to 5 days|
|Duration of action||3 days|
|E number||E480 (thickeners, ...)|
|CompTox Dashboard (EPA)|
|Chemical and physical data|
|Molar mass||444.56 g/mol g·mol−1|
|3D model (JSmol)|
|Melting point||153 to 157 °C (307 to 315 °F)|
|Solubility in water||1 in 70 parts mg/mL (20 °C)|
Docusate, also known as docusate salts or dioctyl sulfosuccinate, is a laxative of the stool softener type used to treat constipation. It is considered a good choice in children who have hard feces. Use for constipation, however, is poorly supported by evidence. It may be taken by mouth or used rectally. By mouth a bowel movement often occurs in 1 to 3 days, while rectal use may be effective within 20 minutes.
Side effects are uncommon. Rarely, there may be abdominal cramps or diarrhea. Efficacy decreases with long-term use, and may cause poor bowel function. Docusate is acceptable during pregnancy and breastfeeding. It works by allowing more water to be absorbed by the feces. It typically comes in the form of a sodium, calcium, or potassium salt.
It is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health system. It is available as a generic medication and is not very expensive. In the United States, one hundred doses are about US$14. The sodium salt, dioctyl sodium sulfosuccinate, also is used as a food additive, emulsifier, dispersant, and wetting agent, among other uses. In 2016 it was the 127th most prescribed medication in the United States with more than 5 million prescriptions.
Docusate is frequently used to treat constipation, and in painful anorectal conditions such as hemorrhoids and anal fissures, to help avoid pain caused by straining during bowel movements. However, the available evidence does not support its use for these purposes. Multiple studies have found docusate to be no more effective than a placebo for improving constipation. Others have found it to be less useful for the treatment of chronic constipation than psyllium.
The medication may be given to people who are receiving opioid medication, although prolonged use may cause irritation of the gastrointestinal tract. Data supporting its efficacy in treating chronic constipation are lacking.
Docusate sodium may be given by mouth or rectally. It also is used as an emulsifier and dispersant in topical preparations. When taken by mouth it is typically recommended with plenty of water.
Possible side effects are typically mild and include stomach pain, diarrhea, or cramping. Serious allergic reactions may occur with the drug. The most severe side effect of docusate, although very rare, is rectal bleeding.
Dioctyl sodium sulfosuccinate is used as a surfactant in a wide range of applications, often under the name Aerosol-OT. It is unusual in that it is able to form microemulsions without the use of co-surfactants, and it has a rich variety of aqueous-phase behavior including multiple liquid crystalline phases.
Solubility of dioctyl sodium sulfosuccinate in water is 1:70 (14 g/l) at 25 °C, increasing to 1:20 at 70 °C. Solubility is better in less polar solvents: 1:30 in ethanol, 1:1 in chloroform and diethylether, and practically unlimited in petroleum ether (25 °C). It also is highly soluble in glycerol, although this is a rather polar solvent.
The effect of docusate may not necessarily be all due to its surfactant properties. Perfusion studies suggest that docusate inhibits fluid absorption or stimulates secretion in the portion of the small intestine known as the jejunum.[medical citation needed]
Toxicity for different species varies widely, but dioctyl sulfosuccinate biodegrades quickly in soil and water, a typical finding being >90% in 12 to 17 days. In the atmosphere, it is predicted to be removed by a photochemical reaction with an estimated half-life of 18 hours.
Dioctyl sodium sulfosuccinate is a strong irritant for eyes and lungs, and also a skin irritant. Ingestion may cause the side effects described above, such as diarrhea, intestinal bloating, and occasionally cramping pains. Dioctyl sodium sulfosuccinate is not known to be carcinogenic, mutagenic, or teratogenic.
In a 2010 study, dioctyl sodium sulfosuccinate exhibited higher toxicity against bacteria (Vibrio fischeri, Anabaena sp.) and algae (Pseudokirchneriella subcapitata) than did a number of fluorinated surfactants (PFOS, PFOA, or PFBS). Measuring bioluminescence inhibition of the bacteria and growth inhibition of the algae, the ED50 were in the range of 43–75 mg/l. Combinations of the fluorinated compounds with dioctyl sodium sulfosuccinate showed mid to highly synergistic effects in most settings, meaning that such combinations are significantly more toxic than the individual substances.
The substance is highly toxic for rainbow trout with a median lethal concentration (LC50) of 0.56 mg/l after 48 hours for the pure substance. It is only slightly to moderately toxic for rainbow trout fingerlings, and slightly toxic for harlequin rasboras (LC50 27 mg/l of a 60% formulation after 48 hours).
In the U.S., dioctyl sodium sulfosuccinate is available under multiple brand names: Aqualax, Calube, Colace, Colace Micro-Enema, Correctol Softgel Extra Gentle, DC-240, Dialose, Diocto, Dioctocal, Dioctosoftez, Dioctyn, Dionex, Doc-Q-Lace, Docu Soft, Docucal, Doculax, Docusoft S, DOK, DOS, Doss-Relief, DSS, Dulcolax - Stool Softener (not to be confused with another drug marketed under the Dulcolax brand, bisacodyl, which is a stimulant laxative), Ex-Lax Stool Softener, Fleet Sof-Lax, Genasoft, Kasof, Laxa-basic, Modane Soft, Octycine-100, Pedia-Lax, Preferred Plus Pharmacy Stool Softener, Regulax SS, Sulfalax Calcium, Sur-Q-Lax, Surfak Stool Softener, and Therevac-SB. Generic preparations are also available.
In the UK, dioctyl sodium sulfosuccinate is sold under the brand name Docusol (Typharm Ltd) and DulcoEase (Boehringer Ingelheim).
In Australia, dioctyl sodium sulfosuccinate is sold as Coloxyl and Coloxyl with senna.
In India, preparations include Laxatin by Alembic, Doslax by Raptakos Laboratories, Cellubril by AstraZeneca, and Laxicon by Stadmed.