Cetostearyl alcohol
Cetylstearyl alcohol (also Stearolum , CTFA , or Cetearyl Alcohol ) is a trivial name for a mixture of solid aliphatic alcohols , mainly cetyl alcohol (hexadecan-1-ol) and stearyl alcohol (octadecan-1-ol), of animal or vegetable origin. Since these alcohols are often produced by reducing the corresponding fatty acids , they are also referred to as fatty alcohols . But you can also z. B. obtained by hydrolysis of waxes . Cetostearyl alcohol is used in a large number of pharmaceutical and cosmetic preparations, increases the stability of emulsions and improves the texture of preparations.
use
- in ointments and creams (including eye ointments, vaginal creams, nasal ointments , wound ointments , sun cream, etc.)
- in medicated soaps and skin care products
- in the textile industry as a textile auxiliary
- as a foam barrier in detergents
- as a sol medium and to improve the lubricity in water-miscible cooling lubricants
In pharmaceutical preparations, cetostearyl alcohol often replaces whale rat , the use of which the authorities prohibited to protect the sperm whales and which has not been monographed in the pharmacopoeia since 1978 .
properties
Cetostearyl alcohol appears as a waxy mass, tablets, flakes or grains of white to pale yellow in color. Pharmaceutical grades contain at least 40.0 percent stearyl alcohol, the sum of the contents of stearyl alcohol and cetyl alcohol is at least 90.0 percent. The melting temperature is 49 to 56 ° C. Cetostearyl alcohol is practically insoluble in water, soluble in ethanol 96% and petroleum ether ; When melted, it can be mixed with fatty oils , liquid paraffin and melted wool wax . Cetostearyl alcohol has an HLB value of around 1 and is only weakly surface-active (W / O emulsifier).
Cetyl alcohol, C 16 H 34 O
Stearyl alcohol, C 18 H 38 O
Emulsifying cetostearyl alcohol
The emulsifying cetyl stearyl alcohol is a pharmaceutically used mixed emulsifier , which consists of at least 80.0 percent cetyl stearyl alcohol and 7.0 percent of the ionic O / W emulsifiers sodium cetyl stearyl sulfate (type A) or sodium lauryl sulfate (type B). Both Type A and Type B emulsifying cetostearyl alcohol are soluble in hot water to form an opalescent solution, but practically insoluble in cold water. It is part of water-absorbing ointment bases such as the "Hydrophilic Ointment DAB" and hydrophilic bases such as the "Anionic hydrophilic cream DAB".
Trade names
Lanette O (cetostearyl alcohol), Lanette E (sodium cetyl stearyl sulfate) , Lanette N (emulsifying cetyl stearyl alcohol)
Individual evidence
- ↑ European Pharmacopoeia, 8th edition, Grundwerk 2014, p. 2756.
- ↑ Bauer, Frömming, Führer: Pharmazeutische Technologie, 9th edition (2012), Wissenschaftliche Verlagsgesellschaft mBH, p. 164.
- ↑ European Pharmacopoeia, 8th edition, 1st supplement, 2014, pp. 5407 and 5409.
- ↑ HA Schiffter Vintage Sign: To make sure nothing breaks , German pharmacists newspaper, 2016, No. 40, page 94..