58 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS This may also be true because, although most guar gum manufacturers recommend its use in cosmetics in general, concrete information is scarce as are patents and available formulations. Guar gum is used on a sizeable scale in the manufacture of tooth paste to which it imparts slip, so that the paste can be extruded from the tube without applying excessive pressure. Similarly it is used in some shaving creams, where it stabilizes the system, imparts slip in extrusion and on the skin, while shaving, and improves facial skin after feel (16). It lends itself perfectly to be used in emulsified systems: creams and lotions - as a protective colloid, increasing emulsion stability, preventing syneresis, water loss, and phase separation. It also prevents degradation of emulsion due to freeze-thaw conditions which cause the water phase to condense out of the system. For instance, used in an ordinary Triethanolamine Stearate type lotion it gives it a stable viscosity, improved spreadability and imparts to it an agreeable after feel associated with best quince seed formulated lotions. In aerosols dispensing aqueous liquid preparations as a spray or mist it is said to reduce migration of "fog" (16). Guar gum solutions are compatible and mix well with most detergent systems (shampoos, cleansers, etc.) giving them "body" and abolishing or minimizing their harsh after feel. Excellent hair colourants were also prepared using guar gum solution as thickener. Although not an emulsifier - owing to its ready compatibility -guar gum solutions can be used in conjunction with other gums endowed with emulsifying properties. An excellent, stable emulsion was, for instance, prepared in the cold adding 30-40% mineral oil into a 10% solution of polyvinyl alcohol (80% hydrolysis low molecular weight) under vigorous stirring and then adding 3% guar gum solution and mixing to uniformity. When mineral oil was replaced by Shellsol T the resulting emulsion was film forming. Self-emulsifying grades of guar gum are also available. Dry face mask mixes were easily and conveniently prepared using guar gum plus additives which in such system may even be heat- and moisture-sensitive. In use, the mixes need only to be stirred into a sufficiency of cold or tepid water (half a cupful) to produce a rich creamy paste. It is hoped that these few examples will stimulate the interest of cosmetic formulators, and the content of this paper will help them in solving, successfully, the ensuing problems. (Received: 18th August 1969)

GUAR GUM AND ITS APPLICATIONS 59 REFERENCES (1) Smith, F. and Montgomery, R. Chemistry of plant gums and mucilages (1959). (Reinhold Publishing Corp., New York). (2) "Guartec" (1963). (General Mills Inc.). (3) "Jaguar", (1962). (Stein, Hall & Co. Inc.). (4) Kirk and Othmer. "Gums, Natural" by M. Gliksman. Encyclopaedia of Chemical Technology, 10 (1966). (5) I-Ieyne, Eileen and Whistler, Roy L. J. Am. Chem. Soc. 70 2249 {1948). (6) Ahmed, Z. F. and Whistler, R. L. J. Am. Chem. Soc. ?9. 2524 {1950). (7) Swanson, J. W. J. Am. Chem. Soc. 71 1510 {1945). (8) Rafique, C. M. and Smith, F. J. J. Am. Chem. Soc. ?9., 4684 (1950). {9) Moer, G. Jr. and Meer, W. A. Am. Perturner 77 49 {4, 1962). (10) Natural Plant Hydrocolloids. Roy L. Whistler. "Guar Gum, Locust Bean Gum and Others" {Advances in Chemistry Seriet 11. Am. Chem. Soc.) {1954) (11) Brit. Pat 1 076 420. (12) Gerding, P. W. and Sperandio, G. J. J. Am. Pharm. Assoc. Pract. Ed. t5 856 {1954) (13) Carlson, W. A., Ziegenfuss, E. M. and Overton, J. D. Compatability and manipulation of guar gum. Food Technol. 16 50 (10, 1962). (14) Eherton, L. E. Platz, P. E. and Cosgrove, F. P. Drug Standards. 9.8 No. 2, 42-47 (19SS). (15) $chimmel Brief No. 401. (September, 1968). (16) Bulletin 1 GF-5 Supercol Guar Gum - Cosmetic and Pharmaceutical Uses. (General Mills Inc.). DISCUSSION MR. C. A. WATSON: In reply to the statement that guar is used in several leading dentifrices in the U.S.A. I wish to state that we have not succeeded in making satis- factory toothpastes because of its incompatibility with glycerine, neither have we found the Jaguar products fully satisfactory. I am not aware of any major U.S.A. toothpaste brand which relies on guar gum thickener. THE LECTURER: I do not know which companies are concerned as I have that information from the guar gum manufacturers' handout. They just state categorically that a few leading American companies use guar gum as a hydrocolloid in their toothpastes, and that has struck me as being feasible. You probably know better but, judging from its properties, guar gum would seem very useful because of its relatively high yield value, quick shear recovery and generally good compatibility. I have not tried it in toothpaste systems. However, I have tried guar gum in various emulsified systems - creams and the like - and in my experience it has proved quite compatible with all polyols used in cosmetics up to a level of approx. 5%. MR. D. N. MXDDOX: Natural gums such as tragacanth are often highly contamina- ted with bacteria and as a result products containing them are difficult to preserve. Is guar gum normally contaminated and, if so, can you give some idea of the bacterial count? THE LECTURER: It should not be contaminated in this way, because one of the processes which the natural guar gum undergoes is autoclaving. This expedient is directed not so much against the bacteria, as against the enzymes which could have