FAO Nutrition Meetings Report Series No. 40A,B,C WHO/Food Add./67.29 TOXICOLOGICAL EVALUATION OF SOME ANTIMICROBIALS, ANTIOXIDANTS, EMULSIFIERS, STABILIZERS, FLOUR-TREATMENT AGENTS, ACIDS AND BASES The content of this document is the result of the deliberations of the Joint FAO/WHO Expert Committee on Food Additives which met at Rome, 13-20 December, 19651 Geneva, 11-18 October, 19662 1 Ninth Report of the Joint FAO/WHO Expert Committee on Food Additives, FAO Nutrition Meetings Report Series, 1966 No. 40; Wld Hlth Org. techn. Rep. Ser., 1966, 339 2 Tenth Report of the Joint FAO/WHO Expert Committee on Food Additives, FAO Nutrition Meetings Report Series, 1967, in press; Food and Agriculture Organization of the United Nations World Health Organization 1967 POLYVINYLPYRROLIDONE Synonyms Polyvidone; PVP Empirical formula (C6H9ON)n Structural formulaMolecular weight of unit: 111.1 Average molecular weight range of the polymer between 11 500 and 25 000. Definition Polyvinylpyrrolidone contains not less than 95 per cent. (C6H9ON)n Description Fine white or light yellow powder, odourless, tasteless and slightly hygroscopic. Uses Clarifying agent. Biological Data Biochemical aspects Polyvinylpyrrolidone (PVP) is a macromolecular polymer of N-vinylpyrrolidone. It is metabolically inert in rat, dog and man as shown by experiments using 14C- or 131I-labelled PVP (Ravin et al., 1952). It has been widely used as plasma expander. The excretion of PVP is inversely related to increasing molecular weight. The glomerulus can excrete all PVP of molecular weight 40 000 or below within a few days (Ravin et al., 1952). Low molecular weight PVP adsorbs various substances, e.g. bacterial toxins, inorganic poisons. barbiturates, vitamins and hormones in the blood, either reducing their toxicity or prolonging their activity (Weese, 1944). In blood it is mainly attached to the upsilon globulins (Bennhold & Schubert, 1944). The reticuloendothelial system retains PVP with a molecular weight in excess of about 100 000 for a long time (Ravin et al., 1952; Heinrich et al., 1966; Weese & Fresen, 1952).PVP is also accumulated in the mitochondria of the kidneys (Traenckner, 1954), In the PVP-storing cells it is surrounded by carbohydrates and lipids in a capsule-like manner, perhaps due to coacervation processes (Hübner, 1960). The problem of whether the extremely long storage of PVP in the body produces toxic effects is open to discussion (Altemeir et al., 1954; Ammon & Miller, 1949). Transfer of intravenously injected PVP to the brain or through the placenta was not observed (Ravin et al, 1952). I.v. injection of 131I-labelled PVP has been clinically used to detect gastrointestinal protein losses. PVP of m.w. 11 500 is not absorbed from the intestinal tract by man or by rat (Angerwall & Berntsson, 1961). PVP of m.w. 16 000 is not absorbed from the gastrointestinal tract by guinea-pigs (Scheffner, 1955). Acute toxicity Animal Route Molecular weight LD50 References (mg/kg body-weight) Rat oral 10 000-30 000 >40 000 Scheffner, 1955 Badische Anilin und Sodafabrik, 1958 Mouse oral >40 000 Scheffner, 1955 Badische Anilin und Sodafabrik, 1958 i.p. 12 000-15 000 Angerwall & Berntsson, 1961 Rat oral 40 000 100 000 Burnette, 1962 Shelanski et al., 1954 Guinea-pig oral 40 000 100 000 Burnette, 1962 Shelanski et al, 1954 Oral PVP (m.w, up to 40 000) in higher doses causes diarrhoea, the minimal effective dose being 0.5 g/kg body-weight for cats, and 1-2 g/kg body-weight for dogs (Scheffner, 1955) Short-term studies PVP molecular weight up to 40 000 Dog. Four groups of 4 beagle dogs were, fed 0, 2, 5, and 10 per cent. PVP (m.w. 38 000) for 2 years. There were no differences in weight gain, food consumption and results of the of blood and urine. At the end of the 2-year period all animals were in good health and histological examination disclosed no specific changes, except for swollen RES cells in the mesenteric and other lymph nodes of all test groups, especially at the 10 per cent. level. No PVP was detected in the urine. No malignant tumours were detected (Burnette, 1962). In 2 similar feeding experiments using a total of 32 dogs and lasting for 1 year no adverse effects could be detected. The intestines, spleens and livers of all animals ware shown to be free of PVP, but PVP was demonstrated in the mesenteric lymph nodes of all animals, including the controls (Burnette, 1962). Several other short-term studies in rat, cat and dog showed no toxic effects (Scheffner, 1955). PVP molecular weight 220 000-1 500 000 Dog. Two dogs were given oral doses of 5 g/kg body-weight PVP (m.w. 220 000 and 1 500 000) for 1-1/2 weeks and 2 weeks respectively without any abnormal findings (Scheffner, 1955). Long-term studies Rat. Groups of rats were fed diets containing 0, 1 and 10 per cent. PVP (m.w. 38 000) for 2 years. No toxic effects or gross or histological changes were noted which could be attributed to the test compound. There was no evidence of absorption of PVP from the intestinal tract (Badische Anilin and Sodafabrik, 1958; Burnette, 1962). Comments There is a large amount of experience available on the parenteral administration of PVP to man. I.v. injected PVP having a molecular weight exceeding 40 000 is stored in the body for a long time, mainly in the RES. Orally administered PVP is not absorbed from the Intestinal tract except perhaps in small quantities that may enter the intestinal lymph nodes. Further feeding experiments in order to clarify the problem of possible storage or PVP intestinal lymph nodes and studies on the possible effects of PVP on the absorption of nutrients are required within the next 2 years. Evaluation The animal data provided do not allow the use of the normal procedure for arriving at an acceptable daily intake for man. The evaluation is based provisionally on the large clinical experience in man and the known metabolic inertness of this substance. No unconditional acceptance can be given because of probable accumulation in the lymph nodes. Estimate of acceptable daily intake for man mg/kg body-weight Conditional acceptance 0-1 Further work required Further feeding experiments in order to clarify the problem of a possible storage of PVP in the intestinal lymph nodes. Studies on the possible effects of PVP on the absorption of nutrients. REFERENCES Altemeir, W. A,, Schiff, L., Gall, E. A., Gluseffi, J., Freiman, D., Mindrum, G. & Braunstein, H. (1954) Amer. Med. Assoc. Arch. Surg., 69), 300 Ammon, R. & Müller, W. (1949) Dtsch. Med. Wsch., 15, Angerwall, L. & Berntsson, S. (1961) J. Inst. brwnig., 67, 353 Badische Anilin und Sodafabrik A. G. (1958) Unpublished report submitted to WHO Bennhold, H. & Schubert, R. (1944) Klin. Wschr., 23, 30 Burnette, L. W. (1962) Proc. Sci. Sect. Toilet Goods Assoc., 38, 1 Heinrich, H. C., Gabbe, E. E., Nass, W. P. & Becker, K. (1966) Klin. Wschr., 44, 488 Hübner, G. (1960) Virchows Arch. Path. Anat., 333, 29 Ravin, H. A., Seligman, A. M. & Fine, J. (1952) New England. J. med., 247, 921 Scheffner, D. (1955) Thesis, University of Heidelberg, summary submitted to WHO Shelanski, A, A., Shelanski, M. V. & Cantor, A. (1954) J. Soc. Cosm. Chem., 5 129 Traenckner, K. (1954) Z. ges. exp. Med., 123, 101 Weese, H. (1944) Med. Z., 1, 19 Weese, H. & Fresen, O. (1952) Zieglers Beitr., 112, 44
See Also: Toxicological Abbreviations POLYVINYLPYRROLIDONE (JECFA Evaluation)