Sodium Lauryl Sulfate

Category

Anionic Surfactant; Detergent; Emulsifying Agents; Skin Penetrant; Tablet and Capsule Lubricant; Wetting Agents

Molecular Formula

C12H25NaO4S

Molecular Weight

288.38

Grade

Pharmceutical Excipients

Description

Sodium lauryl sulfate consists of white or cream to pale yellow colored crystals, flakes, or powder having a smooth feel, a soapy, bitter taste, and a faint odor of fatty substances.

UNII

368GB5141J

Chemical Name

Sulfuric acid monododecyl ester sodium salt

CAS Number

151-21-3

Synonyms

Dodecyl alcohol hydrogen sulfate, sodium salt; dodecyl sodium sulfate; dodecylsulfate sodium salt; Elfan 240; lauryl sodium sulfate; lauryl sulfate, sodium salt; monododecyl sodium sulfate; natrii laurilsulfas; sodium dodecyl sulfate; sodium n-dodecyl sulfate; sodium laurilsulfate; sodium monododecyl sulfate; sodium monolauryl sulfate; SDS; SLS; sulfuric acid monododecyl ester, sodium salt; Texapon K12P

Administration route

Oral, sublingual, topical and vaginal

Dosage Form

Dental preparations; oral capsules, suspensions, and tablets; topical and vaginal preparations

Stability and Storage Conditions

Sodium lauryl sulfate is stable under normal storage conditions. However, in solution, under extreme conditions, i.e. pH 2.5 or below, it undergoes hydrolysis to lauryl alcohol and sodium bisulfate. The bulk material should be stored in a well-closed container away from strong oxidizing agents in a cool, dry place.

Source and Preparation

Sodium lauryl sulfate is prepared by sulfation of lauryl alcohol, followed by neutralization with sodium carbonate.

Applications

Sodium lauryl sulfate is an anionic surfactant employed in a wide range of nonparenteral pharmaceutical formulations and cosmetics. It is a detergent and wetting agent effective in both alkaline and acidic conditions. In recent years it has found application in analytical electrophoretic techniques: SDS (sodium dodecyl sulfate) polyacrylamide gel electrophoresis is one of the more widely used techniques for the analysis of proteins; (1) and sodium lauryl sulfate has been used to enhance the selectivity of micellar electrokinetic chromatography (MEKC).

Safety

Sodium lauryl sulfate is widely used in cosmetics and oral and topical pharmaceutical formulations. It is a moderately toxic material with acute toxic effects including irritation to the skin, eyes, mucous membranes, upper respiratory tract, and stomach. Repeated, prolonged exposure to dilute solutions may cause drying and cracking of the skin; contact dermatitis may develop.Prolonged inhalation of sodium lauryl sulfate will damage the lungs. Pulmonary sensitization is possible, resulting in hyperactive airway dysfunction and pulmonary allergy. Animal studies have shown intravenous administration to cause marked toxic effects to the lung, kidney, and liver. Mutagenic testing in bacterial systems has proved negative.Adverse reactions to sodium lauryl sulfate in cosmetics and pharmaceutical formulations mainly concern reports of irritation to the skin or eyes following topical application. Sodium lauryl sulfate should not be used in intravenous preparations for humans. The probable human lethal oral dose is 0.5-5.0 g/kg body-weight. LD50 (mouse, IP): 0.25 g/kg LD50 (mouse, IV): 0.12 g/kg LD50 (rat, oral): 1.29 g/kg LD50 (rat, IP): 0.21 g/kg LD50 (rat, IV): 0.12 g/kg

Incompatibilities

Sodium lauryl sulfate reacts with cationic surfactants, causing loss of activity even in concentrations too low to cause precipitation. Unlike soaps, it is compatible with dilute acids and calcium and magnesium ions. Sodium lauryl sulfate is incompatible with salts of polyvalent metal ions, such as aluminum, lead, tin or zinc, and precipitates with potassium salts. Solutions of sodium lauryl sulfate (pH 9.5-10.0) are mildly corrosive to mild steel, copper, brass, bronze, and aluminum.