POLYVINYLPYRROLIDONE, ITS MANUFACTURE, PROPERTIES AND USE IN COSMETICS By I. GREENFIELD, B.$c., A.R.I.C.* A lecture delivered to the Society on Friday, February 1st, 1957 1. HISTORICAL NOTE POLYVINYLPYRROLIDONE WAS first synthesised in Germany by Walter H,•C. CH,• I I I H•C CO -- Fig. 1. Structure of Polyvinylpyrrolidone. Reppe during the late 1930's •'"a and was initially evaluated there as a possible blood plasma substitute during World War II. • It has, of course, been known for many years that hydrophilic colloids could be retained in the blood stream long enough to be suitable as replacement fluids for natural blood, and during the first World War substances such as gum arabic were used for this purpose. These early matehals, although useful in an emergency, all exhibited harmful side effects, and at the beginning of World War II two German workers, Weese and Hecht, evaluated a number of the newer water-soluble colloidal high polymers with a view to developing an improved plasma substitute without the earlier defects. They finally settled on polyvinylpyrrolidone, • and a plasma substitute based on this was used quite widely by the German medical services during the war, and similar materiMs have indeed been used subsequently in America, Europe and elsewhere. From this initial use a number of other medical applications have been developed, and it is not surprising that uses outside the medical field have received a good deal of attention. To date, industrial uses for the polymer * British Oxygen Research & Development, Ltd., London, S.W. 19. 196

POLYVINYLPYRROLIDONE IN COSMETICS 197 have been developed in the textile industry, photographic industry and so on. It is with one group of such uses, in the formulation of cosmetics and toilet preparations, that we are now concerned. It should be emphasised at the outset that special grades of polyvinyl- pyrrolidone are required for internal medical use, and materials supplied for industrial and cosmetic purposes should not be used in pharmaceuticals. 2. SYNTHESIS SYNTHESIS OF POLYVINYLPYRROLIDONE LIMESTONE I I • CARBON LIME DIOXIDE I I C.•LCIUM CARBIDE ACETYLENE CH•CH COKE WATER METHYL [• • ALl-_9 HOL AIv•MONL• FORMALDEHYDE 0,.•. CH 2 BUTYN•[-1:4 DIOL HOH 2 • C---C C CH 2 OH BUTANE 1:4 DIOL ..• c-•. c.• c.•o. • BUTYROLAC tONE HC,,. /CO 20 • l • PYRR(•LIDONE I I N VINYLPYRROUDONE CH = CH::) POLYMER ISATION AIR NITROGEN OXYGEN PO LYVINYLP.YRROLIDONE Fig. 2. Synthesis of Polyvinylpyrrolidone. Polyvinylpyrrolidone is primarily derived from limestone, coke, water and air, and is therefore potentially available in unlimited quantities. As it is completely synthetic there is little variation in the properties or quality of the material, which can be controlled during manufacture. The polymer is prepared by the following series of reactions, two of which involve the use of acetylene under elevated pressures. It is perhaps worth mentioning that in handling acetylene, explosive