Lanette cream

Hydrophilic cream 0/w cream Nonionic hydrophilic cream SR DAC (Table 12.33), Lanette cream I and II (Table 12.34)... 

A known incompatibility by charge differences is the reaction of anionic surfactants with cations. Sodium cetostearyl sulfate (as compotmd of emulsifying cetostearyl alcohol type A, also known as Lanette N) and sodium lauryl sulfate (as compotmd of emulsifying cetostearyl alcohol type B, also known as Lanette SX) may cause this incompatibility. As a result the lipophilic and hydrophilic phases separate and the cream becomes almost fluid. An example of this effect is the incorporation of chlorhexidine gluconate in lanette creams. The anionic part of the emulsifier precipitates with the chlorhexidine gluconate, which not only decreases the physical stability of the cream but also the effectiveness of chlorhexidine. 

The formulation in Table 12.33 represents a non-ionic-active hydrophilic cream base. It contains a liquid wax (ethylhexyl laurate), which is well absorbed by the skin. The robust cream base tolerates processing of organic solvents and of phenols such as salicylic acid, in spite of its nonionic character. Lanette creams 12.34 are anionic-active bases. The two formulations differ in their consistency. The higher amount of emulsifying cetostearyl alcohol in Lanette cream II leads to a more stiff cream. It is especially suitable for preparations with a larger quantity of liquids. 

Surfactants such as sulfated fatty alcohols may be hydrated to a higher extent than the fatty alcohols alone and thus stabilize o/w emulsions. The eombination of an anionic and a nonionic srrrfactant has proved to be partieularly effeetive, sinee the electrostatic repulsion forces between the ionie surfaetant moleeules at the interface are reduced by the incorporation of nonionic molecules, thus improving the emulsion stability. The combination of cetyl/stearyl sulfate (Lanette E) and eetyl/ stearyl alcohol (Lanette 0) to yield an emulsifying eetyl/stearyl aleohol (Lanette N) is an example of this approach. The polar properties of this srrrfactant mixtrrre are dominant, and o/w creams are formed. In contrast to w/o systems, the stabilizing effect of the surfactant mixtirre is not mainly due to adsorption at the interfaee. Instead, the mixed surfactants are highly hydrated and fonn a lamellar network, whieh is... 

The samples of the formulated creams (19) containing 0.1-0.2 mequiv of alkaloid halides. Salicylic acid, hexochlorophane or methyl salicylate dispersed in cetamacrogol, cetrimide or lanette wax, are dissolved in 35 ml of anhydrous acetic acid (with addition of 5 ml of 3% Hg acetate in the example of alkoids) or dimethylformamide, and are titrated with 0.1 M HCI04 or... 

Lanette wax or emulsifying wax consists of cetyl and stearyl alcohol with 10% sulfated esters of fatty alcohols because of its emulsifying properties it is often used as a substitute for lanolin in creams. Hjorth and Trolle Lassen (1963) described hypersensitivity to Lanette wax in 0.8% of eczema patients. Concomitant sensitivity to lanette wax and to lanolin was rare. 

The lipophilic base is formulated in the same way as hydro-phobic ointments, see Sect. 12.5.2. The o/w emulsifiers are usually the same as in o/w creams for example cetomacrogol emulsifying wax and lanette emulsifying wax (lanette wax SX or N). As these bases are anhydrous... 

Crlet 3 Emalex 703 Emalex 705 Emalex 707 Emalex 709 Emalex 710 Emalex 712 Emalex 715 Emalex 720 Emalex 725 Emalex 730 Emalex 750 Emalex 1605 Emalex 1610 Emalex 1615 Emalex 1620 Emalex 1625 Emalex 1805 Emalex 1810 Emalex 1815 Emalex 1820 Emalex 1825 Lanette E PH Simubol 78 Simulsol 98 Simulsol CS wetting agent, creams/lotions Abil B 8863 Caprol 3GO Caprol PGE 860 Cola Lux LO Crodamol GTCC DeTAINE PB HallStai PEG 400 DL Hall-Star PEG 400 DO HallStai PEG 400 DS HallStai PEG 400 ML HallStai ... 

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