Lanolin Alcohols
(lan' oh lin al' ka hols).
» Lanolin Alcohols is a mixture of aliphatic alcohols, triterpenoid alcohols, and sterols, obtained by the hydrolysis of Lanolin. It may contain not more than 0.1 percent of a suitable antioxidant.
Packaging and storage— Preserve in well-closed, light-resistant containers, and store at controlled room temperature.
Labeling— Label it to indicate the name and quantity of any antioxidant added.
Identification— Dissolve 0.5 g in 5 mL of chloroform, and add 1 mL of acetic anhydride and 2 drops of sulfuric acid: a green color is produced.
Acidity and alkalinity— Boil 10 g with 100 mL of water for 5 minutes, with frequent stirring. Remove the source of heat, add 0.5 mL of phenolphthalein TS, and stir: no pink color is produced. Add 0.5 mL of methyl orange TS, and stir: no red color is produced.
Loss on drying 731 Dry it at 105 for 1 hour: it loses not more than 0.5% of its weight.
Residue on ignition 281: not more than 0.15%.
Copper— Heat 5.0 g over a small flame until charred, ignite the residue at about 550, and dissolve the ash in 5 mL of hydrochloric acid, with the aid of heat. Cool, dilute with water, render alkaline with ammonium hydroxide, boil to remove the excess of ammonia, add a few drops of bromine TS, boil again, and filter. To the filtrate add 1 mL of sodium diethyldithiocarbamate solution (1 in 1000), a few drops of 6 N ammonium hydroxide, and sufficient water to bring the volume to 50 mL. The resulting color is not darker than that produced by adding 1 mL of the sodium diethyldithiocarbamate solution and a few drops of 6 N ammonium hydroxide to 2.5 mL of a 0.00393% solution of cupric sulfate, and diluting with water to 50 mL (5 ppm).
Acid value 401: not more than 2.0.
Hydroxyl value 401: between 120 and 180.
Peroxide value 401: not more than 15. Take from the test substance wedge-shaped pieces whose base consists of part of the surface. Melt the pieces before carrying out the determination. Before adding the 0.5 mL of saturated potassium iodide solution, cool the solution obtained to room temperature.
Saponification value 401: not more than 12, a 5-g specimen of molten Lanolin Alcohols being refluxed with the alcoholic potassium hydroxide for 4 hours.
Content of sterols (as cholesterol)— Melt 20 g of Lanolin Alcohols on a water bath, mix, and allow to cool. Dissolve about 100 mg, accurately weighed, in 12 mL of warm (about 60) 90 percent alcohol. Allow to stand for 18 hours, pass through a medium-porosity, sintered-glass filter, and wash the residue with two 15-mL portions of 90 percent alcohol. Combine the filtrate and washings, add 20 mL of a freshly prepared 1 in 100 solution of digitonin in 90 percent alcohol, and warm to 60. Allow to cool, pass through a medium-porosity, sintered-glass filter with the aid of gentle vacuum, wash the residue with 10 mL of 90 percent alcohol, and dry at 105 to constant weight. Each g of residue is equivalent to 0.239 g of cholesterol: not less than 30.0% of sterols, calculated as cholesterol, is found.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, M.S.
Scientific Liaison
(EXC2010) Monographs - Excipients
USP35–NF30 Page 1840
Pharmacopeial Forum: Volume No. 34(4) Page 1014