Emulsions self-bodying

Nonionic emulsifying wax is used as an emulsifying agent in the production of oil-in-water emulsions that are unaffected by moderate concentrations of electrolytes and are stable over a wide pH range. The concentration of wax used alters the consistency of a product owing to its self-bodying action at concentrations up to about 5% a product is pourable. 

Stable o/w creams prepared with ionic or nonionic emulsifying waxes are composed of (at least) four phases (Fig. 7.20) (f) dispersed oil phase, (2) crystalline gel phase, (3) crystalline hydrate phase, and (4) bulk aqueous phase containing a dilute solution of surfactant. The interaction of the surfactant and fatty alcohol components of emulsifying mixtures to form these stmctures (body) is critical. It is also time-dependent, giving the name self-bodying to these emulsions. The overall stability of a cream is dependent on the stability of the crystalline gel phase. 

Certain guidelines have been devised for the formulation of self-bodied emulsions ... 

Wax BP, Cetomacrogol Emulsifying Wax BP and Cetrimide Emulsifying Wax (BP) are ready prepared mixtures for extemporaneous use. When these or similar mixtures are used the resultant emulsions are mobile at low emulsifier concentrations and semi-solid at moderate concentrations (about 10% or less of the total weight of the emulsion). The process whereby the surfactant mixture imparts the semi-solid characteristics over a period of time has been termed self-bodying [92-94], the essential feature of which is the introduction of a significant elastic... 

In a paper on the self-bodying action of alkyltrimethylammonium bromide-cetostearyl alcohol mixed emulsifiers, Barry and Saunders [100] discuss the sequence of events in the preparation of liquid paraffin-in-water emulsions containing these components. The gel structure in the continuous phase is clearly responsible for the self-bodying. During mixing of a ternary system the... 

The problem with the semi-solid, self-bodied emulsion systems has been to measure their consistency. Measurements from continuous shear measurements, as they are the result of structural breakdown in the systems under study, have to be treated with some degree of caution. In order to obtain a true measure of consistency or body the systems should be tested in their native state, this requiring a method of measurement which does not disrupt the structures in the emulsion. Thus so-called creep measurements may be applied in which the emulsions are subject to only relatively minor deformities. In creep a shear is quickly imposed on the sample and maintained at a constant level the time-dependent strain or compliance response to this steady stress provides the creep curve. A recovery curve is obtained on removal of the stress, a typical diagram showing the profile for creep and recovery is given in Fig. 8.38. 

In self-bodied emulsions the structures take a finite time to reach a state of equilibrium and thus there is this additional ageing factor related to the continuous phase, creep compliances falling and viscosities rising [196]. An idealized diagram of the relationship between rj and J and the mixed emulsifier concentration in oil-in-water emulsions is shown in Fig. 8.40. 

Features Self-bodying produces stable emulsions unaffected by alkali or adds ... 

Chem. Descrip. C14-22 alcohol and C12-20 alkyl glucoside Uses Emulsifier for personal care low-vise, emulsions including body lotions, fluid creams, sun sprays and self-tan products, fluid foundations Features Natural provide Montanov S [Seppic]... 

There is now a solid body of available knowledge to indicate that the general features of biopolymer self-assembly in bulk aqueous solutions can account for various detailed aspects of the stability, rheology and microstructure of oil-in-water emulsions (and foams) stabilized by the same kinds of biopolymers (Dickinson, 1997, 1998 Casanova and Dickinson, 1998 Dickinson et al., 1997, 1998 Semenova et al., 1999, 2006 van der Linden, 2006 Semenova, 2007 Ruis et al., 2007). In particular, the richness of the self-assembly and surface-active properties of the... 

An emulsion base or a waxy-type self-emulsifier to develop structure or false body in suspension... 

CAS 67762-30-5, 68439-49-6 EINECS/ELINCS 267-009-1 Uses Bodying agent, coemulsitier, o/w emulsifier, emulsion stabilizer for personal care prods, incl. hand and body care, sun care, self-tanners, shaving prods., facial skin care, hair conditioners Features High quality, readily emulsifiable... 

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