IPCS INCHEM Home

    POLYVINYLPYRROLIDONE (PVP)

    Explanation

         This substance was evaluated for acceptable daily intake for man
    (ADI) by the Joint FAO/WHO Expert Committee on Food Additives in 1966
    and 1973 (see Annex I, Refs. 12 and 32). Toxicological monographs were
    issued in 1966 and 1973 (see Annex I, Refs. 13 and 33). Since the
    previous evaluation, additional data have become available and are
    summarized and discussed in the following monograph.

    BIOLOGICAL DATA

         Povidone is the generic name for polyvinylpyrrolidone (PVP). It
    is the soluble homopolymer of N-vinyl-2-pyrrolidone. As a food
    additive it appears as the form identified as K-30. To clarify the
    discussion, the relationship of K-30 to other marketed forms is as
    follows:

                                                                        

       Form              K-range*        Average molecular weight
                                                                        

    K-15 or 17            12-18                    10 000
    K-30                  26-35                    40 000
    K-90                 80-100                   360 000
                                                                        

    *     Note: based on viscosity.

         It should be noted that the data described in this evaluation
    include some studies of povidone having molecular weights other than
    that of K-30.

         Another related product is crospovidone - chemically
    identified as polyvinylpolypyrrolidone or cross-linked, insoluble
    polyvinylpyrrolidone. It is the insoluble, cross-linked homopolymer of
    N-vinyl-2-pyrrolidone. Crospovidone is not the subject of the present
    evaluation.

    BIOCHEMICAL ASPECTS

    Absorption

         Loehry et al. (1970) measured the permeability of the rabbit
    small intestine to water soluble molecules over a range of molecular
    weights from 60 to a molecular weight of 80 000. They reported a well
    correlated inverse log/log linear relationship between absorption and
    molecular weight. The amount of povidone (average molecular weight
    33 000) that was cleared from the lumen by blood was 0.39% of the urea

    cleared from the lumen by blood. If urea is completely absorbed from
    the intestine, then povidone of this average molecular weight is 0.39%
    absorbed.

         Hanka (1971) detected povidone in the portal venous blood of
    rabbits following intestinal perfusion with a solution containing
    povidone (av. mw 40 000).

         Other studies of the gastrointestinal absorption of povidone have
    usually been associated with conventional toxicity studies that have
    been conducted. Scheffner (1955) reported that povidone (av. mw
    16 000) was not absorbed from the gastrointestinal tract of guinea-
    pigs. It was reported that, following the oral administration of
    isotopically labelled povidone (av. mw 40 000 and 70 000) to rats,
    less than 0.5% of the activity was absorbed from the gastrointestinal
    tract (Shelanski, 1953; Burnette, 1962). In a group of rats fed diets
    containing 1% and 10% povidone (av. mw 38 000) for two years, no
    evidence of absorption of povidone from the gastrointestinal tract was
    observed (Shelanski, 1957; Burnette, 1962). Angervall & Berntsson
    (1961) reported that povidone (av. mw 11 500) was not absorbed from
    the gastrointestinal tract of man and rat. Burnette (1962) reported
    that in a group of beagles fed 2.5% and 10% povidone (av. mw 38 000)
    in the diet for one year, povidone was found in the mesenteric lymph
    nodes indicating gastrointestinal absorption.

    Distribution

         Information on the distribution of povidone within the body comes
    primarily from studies following its intravenous or intraperitoneal
    administration. Ravin et al. (1952) administered intravenous infusions
    of varying average molecular weights to rabbit, rat, dog and man.
    Cells of the reticuloendothelial (RES) retained povidone; the higher
    molecular weight molecules were retained the longest. Povidone with an
    average molecular weight of less than 40 000 left the body within a
    few days. Fresen & Weese (1952) reported on the presence of povidone
    (av. mw 38 000) in the RES as did Jeckeln (1952) for povidone (av. mw
    40 000). Others have also made similar reports (for example, Frommer,
    1955; Heinrich et al., 1966). Povidone storage in the RES is as a
    result of its incorporation into macrophages by pinocytosis (Pratten &
    Lloyd, 1979). This incorporation gives rise to the vacuolated
    appearance which has led to the description of "foam cells". The
    earlier assumption that the molecules were stored in the mitochondria
    (Traenckner, 1954) is incorrect (Wessel et al., 1974).

         Povidone of varying molecular weights was reported not to pass
    the blood-brain as well as the placental barriers (Ravin et al.,
    1952).

    Elimination

         The elimination of povidone has been studied by a number of
    investigators, again mostly following intravenous and intraperitoneal
    administration. The elimination of varying molecular weights has been
    tabulated from the world literature by Wessel et al. (1974). The T 1/2
    for the elimination of povidone in the average molecular weight range
    of 40 000 has been reported to be as low as 12 hours and as high as 72
    hours. The glomerulus can clear povidone of a molecular weight of at
    least 25 000 and perhaps as high as 40 000 and the peritubular
    capillaries are permeable to even larger molecules of povidone
    (Gartner et al., 1968).

    TOXICOLOGICAL STUDIES

    Carcinogenicity studies

         Hueper (1957, 1959, 1961) reported on three studies involving
    povidone of various molecular weights.

         In the first study, Hueper (1957) utilized four forms of povidone
    having average molecular weights of 20 000, 22 000, 50 000 and
    300 000. In one series four povidones were implanted in powder form
    subcutaneously into the nape of the neck in C57 black mice and
    Bethesda black rats. In a second series the same four povidones were
    implanted intraperitoneally in the same two species. In still another
    series, rats were given 2.5 ml of a 7% solution intravenously once a
    week for eight weeks. All animals from all studies were autopsied
    either after dying on study or being sacrificed after 24 months.
    Hueper used the descriptions lymphosarcoma, reticulum cell sarcoma and
    Kupffer cell sarcoma. For purposes of this discussion all will be
    considered as RES sarcomas. The results were as follows:

                                                                        

                               Povidone         RES
    Species     Route          (av. mw)      sarcomas     Carcinomas
                                                                        

    Mouse       Subcut.         20 000         0/50          0/50
                (powder)        22 000         3/50          0/50
                                50 000         0/50          0/50
                               300 000         1/50          0/50

                i.p.            20 000         0/50          0/50
                (powder)        22 000         1/50          0/50
                                50 000         3/50          0/50
                               300 000         0/50          0/50

    Rat         Subcut.         20 000         7/50          0/50
                (powder)        22 000         0/50          1/50
                                50 000         9/50          0/50
                               300 000         7/50          1/50

                i.p.            20 000         7/50          4/50
                (powder)        22 000         2/50          0/50
                                50 000         5/50          0/50
                               300 000        12/50          0/50

                i.v.            20 000         2/50          1/50
                                22 000         0/50          1/50
                                50 000         6/50          1/50
                               300 000         2/50          1/50
                                                                        

         The reported incidence of sarcomas among control mice was 0.4%.
    Among the rats 1/23 of the studied, untreated controls had an RES
    sarcoma. Other "control" rats had been exposed to various metal dusts
    or to dextran and did not provide useful data.

         A similar study was done by Hueper (1959) in which the incidence
    of RES sarcomas was 11/200 in untreated rats. In this study,
    additional samples of povidone within the same molecular weight range
    used previously were studied. The data suggested the development of
    RES sarcomas related to the parenteral administration of povidone as
    well as other polymers including dextran. Again the studies were
    controlled only to a limited extent. There were no manipulation
    controls for any of the groups.

         In the third study Hueper (1961) emphasized molecular size as a
    study criterion. He used povidone "K-17" (molecular weight range
    2000-38 000 with the major fraction being between 5000 and 15 000;
    average mw 10 000) and povidone "K-25" (major fraction of molecular
    weight between 15 000 and 30 000; average mw 18 000) (these averages

    for K-17 and K-25 are somewhat lower than what has been reported since
    then for these forms). He also used for comparison purposes in rats
    two povidones having an average mw of 50 000. One made by GAF and one
    made by BASF. The materials were administered intraperitoneally in
    divided doses over a period from approximately six to 10 weeks.
    Maximum survival was 24 months for rats and 28 months for rabbits (at
    which times the experiments were terminated by sacrificing the
    surviving animals). Results were as follows:

                                                                        

                 Povidone           Total          RES
    Species        type        Administration   sarcomas   Carcinomas
                                                                        

    Rat        K-17                  2 g          3/35        2/35
               K-25                  2 g          1/35        2/35
               50 000 (GAF)          9 g          2/20        0/20
               50 000 (BASF)         9 g          0/30        0/30
               Control                            2/30        3/30

    Rabbit     K-17                62.2 g          0/6         0/6
               K-25                62.2 g          0/6         0/2
               Control                             0/2         0/2
                                                                        

         Hueper concluded that the rabbit may have had less tumours
    because of the ability to filter larger molecules at the glomerulus
    than the rat can.

    Teratogenicity studies

         Povidone K-25 (av. mw less than 40 000) was tested for prenatal
    toxicity in rats. The animals received 10% povidone K-25 added to
    their feed. Substance-containing feed was available ad lib. on days
    0-20 post-coitum. All foetuses were examined for externally
    recognizable skeletal malformation, variations and retardations in the
    case of two-thirds of the foetuses of a litter; the examination
    covered organ malformations, variations and retardations. The pregnant
    animals tolerated administration of substance-containing feed with no
    clinically recognizable symptoms of poisoning. The only observed
    effect was slightly loose faeces. With all other parameters examined,
    no changes, and particularly no damage to the progeny, such as could
    be attributed to administration of K-25 were found (BASF 1977c).

         A similar study was conducted on povidone K-90. The animals
    received 10% K-90 added to their feed. The results were qualitatively
    and quantitatively similar to those observed with povidone K-25 (BASF
    1977d).

         In a special teratogenicity study, injection of povidone (av. mw
    11 500) into the yolk sac of nine-day rabbit embryos (500 mg/embryo)
    did not increase the number of resorptions or malfunctions compared to
    the number of resorptions and malformations induced in saline injected
    embryos (Claussen & Breuer, 1975).

    Mutagenicity and transformation tests in vitro

         Povidone K-30 was tested for mutagenic effects on the germ cells
    of male mice (dominant lethal test) after one intraperitoneal
    application. The animals received a single injection of 3 160 mg
    povidone K-30 (dissolved in aquadest.) per kg body weight in a volume
    of 10 ml/kg. No animals displayed any recognizable symptoms of
    toxicity over the entire test period. The administration of povidone
    K-30 had no effect on the conception rate, average number of
    implantations, percentage of living foetuses or the mutagenicity index
    (BASF 1977e).

         Mutagenicity and transformation tests in vitro employing mouse
    cells (lymphoma L5178Y, TK+/-BUDR and Balb/3T3, respectively)
    demonstrated that PVP at concentrations of 0.5%, 1.0%, 5.0% and 10.0%
    in the media did not cause significant mutagenic or transformation
    effects when compared to non-treated cells (Carchman, 1978).

    Quantification of RES storage

         Frommer (1956) quantified storage of povidone "foam cells"
    following the administration of povidone (av. mw 20 000, 40 000 and
    125 000) in rats. He suggested a threshold existed for storage
    equivalent to the system content of 0.1 g/kg.

    Acute toxicity
                                                                                                   

                                     Average              LD50
    Animal         Route        molecular weight       (mg/kg bw)           References
                                                                                               

    Rat             Oral         10 000-30 000       40 000              Scheffner, 1955;
                                                                         BASF, 1958

    Mouse           Oral                             40 000              Scheffner, 1955;
                                                                         BASF, 1958

                    i.p.                             12 000-15 000       Angervall &
                                                                         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 povidone (av. mw up to 40 000) in high doses caused
    diarrhoea, the minimal effective dose being 0.5 g/kg bw for cats, and
    1-2 g/kg for dogs (Scheffner, 1955).

         Two dogs were given oral doses of 5 g/kg bw povidone (av mw
    220 000 and 1 500 000) for one-and-a-half weeks and two weeks,
    respectively, without any abnormal findings (Scheffner, 1955).

         Four pure bred beagles of each sex were given 0, 25 000, 50 000
    and 100 000 ppm povidone (K-90) in the feed for 28 days. Another group
    of eight animals receiving 100 000 ppm cellulose in the feed were also
    used as control. No toxic effects or pathological changes were noted
    which could be related to the administered substance, except slightly
    increased relative spleen weight was observed in the female animals of
    the 100 000 ppm group (BASF, 1977).

         Povidone K-90 was administered to Sprague-Dawley rats (10
    rats/sex/group) in concentrations of 25 000 and 50 000 ppm in the feed
    over a 28-day test period. No toxic effects or pathological-
    histological changes were noted due to administration of K-90 (BASF,
    1973).

         Povidone was also evaluated for acute toxic effect by rapid
    intravenous administration to beagle dogs (Hazleton Laboratories,
    1970). One animal of each sex was given 0, 1, 3 or 10 g of povidone/kg
    bw. The animals were observed for the subsequent 28 days. No deaths
    occurred at any dose. Immediately following administration, the
    animals showed tremors and/or subconvulsive movements, defaecation,
    salivation, depression and ptosis. There were early sporadic changes
    in transaminases and haematologic values which generally returned to
    normal within 48 hours of the dose and remained essentially within
    normal limits during the remainder of the 28-day observation period.
    Gross and histopathological examinations of brain, spinal cord,
    thyroid, adrenal, heart, lung, thymus, spleen, parathyroid, trachea,
    oesophagus, salivary gland, liver, kidneys, stomach, pancreas, small
    and large intestine, mesenteric lymph nodes, urinary bladder, prostate
    and testes in males, uterus and ovaries in females, bone, peripheral
    nerve, and skeletal muscle were conducted. No histopathological or
    gross pathological changes were reported.

         Four groups of animals, each group consisting of two males and
    two females, were distributed as follows: control, 10% diet of Solka
    Floc;* 2% povidone K-30 plus 8% Solka Floc; 5% povidone K-30 plus 5%
    Solka Floc; 10% povidone K-30. The feeding period was two years. There
    were no reported adverse effects at the end of this treatment.
    Histopathological examination of thyroid, parathyroid, heart, lung,
    rib bone and bone marrow, skin, stomach, small bowel, large bowel,
    liver, gall bladder, spleen, kidneys, lymph nodes, urinary bladder,
    uterus or prostate, left adrenal, pancreas and testes or ovaries were
    conducted. Swollen RES cells in the lymph nodes of the high dose group
    were reported. There was evidence of this in the middle and low dose
    groups and the 10% Solka Floc control, but "less consistently and to a
    lesser degree". No other histopathological findings were reported
    (Burnette, 1962). In two similar feeding experiments using a total of
    32 dogs and lasting for one year, no adverse effects could be
    detected. The intestines, spleens and livers of all animals were shown
    to be free of povidone, but povidone 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; Wolven & Levensten, 1957; Shelanski,
    1958).

    Chronic studies

         Groups of rats (Wistar strain) were fed diets containing 0, 1 and
    10% povidone (mw 38 000) for two years. No toxic effects or gross
    histological changes were noted which could be attributed to the test
    compound (BASF, 1958; Burnette, 1962).

              

    *    Solka Floc = cellulose.

         In another two-year rat feeding test povidone (K-25) was added to
    the feed in concentrations of 50 000 or 100 000 ppm. Groups each of
    100 rats (Sprague-Dawley) equally divided by sex were used in this
    study. The feed intake, body weight, clinical parameters tested (urea,
    GPT, HB, Ery, HT, Leuco, differential blood count, urine status),
    macroscopic organ findings and the absolute and relative organ weights
    (heart, liver, kidneys) did not differ from those of the two control
    groups. No differences were found between average life span of the
    test and the control animals. In all control and test groups, the
    appearance of benign and malignant tumours was within the normal
    limits usually found in rats in long-term investigations in this
    strain of rats. Histological examination of the tissue of the organs
    revealed no changes that could be associated with the feeding test.
    There was no evidence that povidone K-25 or its degradation products
    were stored in either the mucous membrane of the duodenum or the
    intestines or the mesenterial lymph nodes (BASF, 1978b).

    OBSERVATIONS IN MAN

         Daily subcutaneous injections of polyvinylpyrrolidonevasopressin
    in a woman with diabetes insipidus for six years led to a papular
    dermatosis. Polyvinylpyrrolidone was detected in biopsy material (La
    Chapelle, 1966).

         To date, the only chronic toxic effect noted in man upon
    subcutaneous injection has been cutaneous thesaurismosis after
    parenteral doses of 200-1000 g over 3-12 years (La Chapelle, 1966).

         Injection of a povidone-containing medication (Depot-Impletol) in
    a woman resulted in large foreign body granulations in the breast and
    in the epigastric area (Gille & Brandau, 1975).

    Comments

         Only data on the soluble homopolymer of N-vinyl-2-pyrrolidone
    i.e., povidone were evaluated.

         No carcinogenicity has been reported for povidone as a
    consequence of oral administration.

         Studies involving parenteral administration, primarily
    intravenous or intraperitoneal indicate that there may be some storage
    of povidone in the reticuloendothelial system (RES) under certain
    conditions.

         The primary predictor of long-term storage relates to the
    molecular size of povidone in the circulation. That is, if the
    molecular size is such that filtration at the kidney occurs then the
    likelihood of storage is less.

         This leads to a question of povidone's absorption from the
    gastrointestinal tract. It is difficult to determine the exact level
    of povidone's absorption from the gastrointestinal tract. This
    difficulty is due to the fact that the absorption of a compound like
    povidone that is both hydrophilic and lipophobic is dependent on its
    molecular size and weight, and the fact that polymer products such as
    povidone consist of a range of molecular weights. It would appear that
    any povidone absorbed from the gastrointestinal tract would be of the
    size that would be cleared by the kidney thus reducing the likelihood
    of accumulation in the RES. Data from studies of povidone's oral
    absorption, distribution and elimination are needed to test this
    hypothesis. These data could be obtained from studies using
    radiolabelled povidone. Mathematical analyses of data available on
    molecular sizes absorbed from the intestine and filtered at the
    glomerulus may also provide the information sought.

         Since the phenomenon of RES storage may be common to all high
    molecular weight polymers, povidone should also be evaluated from the
    viewpoint of comparing it to other polymers used as food additives.

         The only reported biological effect attributed to oral
    administration of povidone is stool softening or diarrhoea. In long-
    term feeding studies in rats no evidence of carcinogenicity was noted
    as well as no indication of storage in the RES.
    

    EVALUATION

         Establishment of an ADI is deferred pending a review and
    evaluation of existing or new data relating to pharmacokinetics and
    RES storage.
    

    REFERENCES

    Altemeir, W. A., Schiff, L., Gall, E. A., Giuseffi, J., Freiman, D.,
         Mindrum, G. & Braunstein, H. Physiological and pathological
         effects of long-term polyvinylpyrrolidone retention. AMA Arch.
         Surg., 69, 308-314, 1954

    Ammon, R. & Muller, W. The influence of high doses of periston on the
         rabbit, with special consideration of the spleen (Ger.). Dtsch.
         med. Wschr., 74, 465-468, 1949

    Angervall, L. & Berntsson, S. Oral toxicity of polyvinylpyrrolidone
         products at low average molecular weight. J. Inst. Brewing,
         67, 335-336, 1961

    Bennhold, H. & Schubert, R. Uber die plasmaahnlichkeit des periston,
         Klin. Wschr., 23, 30, 1944

    Burnette, L. W. A review of the physiological properties of PVP.
         Proceedings of the Scientific Section of the Toilet Goods
         Association, 38, 1-4, 1960

    Carchman, R. A. In vitro evaluation of PVP and PVP-1 for mutagenicity
         and cell transformation capacities. Unpublished report from the
         Medical College of Virginia, Richmond, Va. Submitted to the World
         Health Organization by GAF Corporation, Wayne, New Jersey, United
         States of America, 1979

    Claussen, U. & Breuer, H. W. The teratogenic effects in rabbits of
         doxycycline, dissolved in polyvinylpyrrolidone, injected into the
         yolk sac. Teratology, 12, 297-301, 1975

    Fresen, O. & Weese, H. Tissular findings in animals following
         perfusion with different collidon fractions (peritoneal periton,
         highly viscous periston). Beitr. path. Anat., 112, 44-62,
         1952

    Gartner, K., Vogel, G. & Ulbrich, M. Pflügers Arch., 298, 303-321,
         1968

    Gille, J. & Brandau, H. Geburtsh U. Frauenheilk., 35, 799-801, 
         1975

    Hanka, R. Intestinal absorption of polyvinylpyrrolidone. Nihon Univ.
         J. Med., 13, 129-146, 1971

    Heinrich, H. C., Gabbe, E. E., Nas, W. P. & Becker, K. Metabolic
         behavior of 131I-labeled polyvinylpyrrolidone in the human body.
         Klin. Wschr., 44, 488-493, 1966

    Huebner, G. On the formation of organ substances in collidon storage.
         Virchows Arch. path. Anat., 333, 29-39, 1960

    Hueper, W. C. Experimental carcinogenic studies in macromolecular
         chemicals. I. Neoplastic reactions in rats and mice after
         parenteral introduction of polyvinylpyrrolidone. Cancer, 10,
         8-18, 1957

    Hueper, W. C. Carcinogenic studies on water-soluble and insoluble
         macromolecules. Arch. Path., 67, 589-617, 1959

    Hueper, W. C. Bioassay on polyvinylpyrrolidone with limited molecular
         weight range. J. nat. Cancer Inst., 26, 229-237, 1961

    Jeckeln, E. Histologic findings in infants after repeated
         administration of periston. Arch. Path. Anat. Physiol., 322,
         529-562, 1952

    Kirsch, P., Dati, F., Freisberg, K. O., Birnstiel, H., Mirea, D. &
         Zeller, H. Report on a study on the effects of Kollidon 90 when
         applied orally to rats over a 25-day period. Unpublished report
         from BASF Gewerbehygiene and Toxikologie, Ludwigshafen, Rhein,
         FRG. Submitted to the World Health Organization by BASF, 1972

    Kirsch, P., Dati, F., Freisberg, K. O., Hempel, K. J., Mirea, D., Peh,
         J., Deckardt, K. & Zeller, H. Report on a study on the effects of
         polyvinylpyrrolidone (Kollidon 90) when applied orally to dogs
         over a 28-day toxicity test period. Unpublished report from BASF
         Gewerbehygiene and Toxikologie, Ludwigshafen, Rhein, FRG.
         Submitted to the World Health Organization by BASF, 1975a

    Kirsch, P., Deckardt, K., Mirea, D., Hempel, K. J. & Merkle, J. Report
         on testing of Kollidon CE5050 for toxicity when administered to
         rats over a 28-day period. Unpublished report from BASF
         Gewerbehygiene and Toxikologie, Ludwigshafen, Rhein, FRG.
         Submitted to the World Health Organization by GAF Corporation,
         Wayne, New Jersey, United States of America, 1975

    La Chapelle, J. M. Thesaurismose cutanée par polyvinylpyrrolidone.
         Dermatologica (Basel), 132, 476-489, 1966

    Leuschner, F., Leuschner, A., Schwerdtfeger, W. & Dontenwill, W. Oral
         toxicity of Kollidon CE5050 in the beagle dog, repeated dosage
         over four weeks. Unpublished report from the Laboratorium Per
         Pharmakologie and Toxikologie, Hamburg, FRG. Submitted to the
         World Health Organization by BASF, 1975

    Leuschner, F., Leuschner, A., Schwerdtfeger, W. & Rogulza, P. Six-
         month toxicity of Kollidon CE5050, batch XXIV 544-1 - called for
         short "Kollidon CE5050" - in beagle dogs when administered by
         stomach tube. Unpublished report from the Laboratorium für
         Pharmakologie and Toxikologie, Hamburg, FRG. Submitted to the
         World Health Organization by BASF, 1975

    Loehry, C. A., Axon, A. T. R., Hilton, P. J., Hider, R. C. & Creamer,
         B. Permeability of the small intestine to substances at different
         molecular weight. Gut, 11, 466-470, 1970

    Lusky, L. M. & Nelson, A. A. Fibrosarcomas induced by multiple
         subcutaneous injections of carboxymethyl-cellulose (CMC),
         polyvinylpyrrolidone (PVP), and polyoxyethylene sorbitan
         monostearate (Tween 60) (Abstract No. 1363). Fed. Proc., 16,
         318, 1957

    Pratten, M. K. & Lloyd, J. B. Effects of temperature, metabolic
         inhibitors and some other factors on fluid-phase and adsorptive
         pinocytosis by rat peritoneal macrophages. Biochem. J., 180,
         567-571, 1979

    Princiotto, J. V., Rubbacky, E. P. & Dardin, V. J. Two-year feeding
         study in dogs with polyvinylpyrrolidone (Plasdone C, PVP-NP-K-
         30), final report. Unpublished report from Chemo Medical
         Consultants, Arlington, Va., United States of America. Submitted
         to the World Health Organization by BASF, 1954

    Ravin, H. A., Seligman, A. M. & Fine, J. Polyvinylpyrrolidone as a
         plasma expander, studies on its excretion distribution and
         metabolism. New Engl. J. Med., 247, 921-929, 1952

    Scheffner, D. Tolerance and side-effects of various Kollidons
         administered by mouth and their behavior in the gastrointestinal
         tract (translation from German), Doctors' Thesis, University of
         Heidelberg, 1955

    Shelanski, A. A., Shelanski, M. V. & Cantor, A. Polyvinylpyrrolidone
         (PVP), a useful adjunct in cosmetics. J. Soc. Cosm. Chem., 5,
         129-132

    Shelanski, M. V. Final two-year report of a chronic oral toxicity
         study with PVP (K-30) in rats. Unpublished report from the
         Industrial Biological Research and Testing Laboratories, United
         States of America. Submitted to the World Health Organization by
         BASF, 1957

    Shelanski, H. A. PVP K-30 14C single dose excretion study. Unpublished
         report from the Industrial Toxicology Laboratories, United States
         of America. Submitted to the World Health Organization by BASF,
         1953

    Shelanski, M. V. One year feeding study in dogs with plasdone,
         Unpublished report from Industrial Toxicology Laboratories.
         Submitted to the World Health Organization by BASF, 1958

    Wessel, W., Schoog, M. & Winkler, E. Polyvinylpyrrolidone (PVP): its
         diagnostic, therapeutic and technical application and
         consequences thereof. Arzneim. Forsch. Drug Res., 21,
         1468-1482, 1974

    Traenckner, K. Experimental studies on periston storage in
         mitochondria of renal tubuli. Z. Ges. Exp. Med., 123,
         101-103, 1954

    Wolven, A. & Levenstein, I. One-year feeding study in dogs with PVP,
         final report. Unpublished report from Leberco Laboratories,
         United States of America. Submitted to the World Health
         Organization by GAF Corporation, Wayne, New Jersey, 1957

    Zeller, H. & Engelhardt, G. Testing of Kollidon 30 for mutagenic
         effects in male mice after a single intraperitoneal application,
         dominant lethal test. Unpublished report from the Gewerbehygiene
         and Toxikologie, Ludwigshafen, Rhein, FRG. Submitted to the World
         Health Organization by BASF, 1977

    Zeller, H. & Peh, J. Report on a study on the effects of Kollidon 25,
         batch 1229 on the prenatal toxicity with rats. Unpublished report
         from BASF Gewerbehygiene and Toxikologie, Ludwigshafen, Rhein,
         FRG. Submitted to the World Health Organization by BASF, 1976a

    Zeller, H. & Peh, J. Report on a study on the effects of Kollidon 90,
         batch 5, on the prenatal toxicity with rats. Unpublished report
         from BASF Gewerbehygiene and Toxikologie, Ludwigshafen, Rhein,
         FRG. Submitted to the World Health Organization by BASF, 1976b

    Zeller, H., Sachsse, K., Kirsch, P., Tobst, P., Birnstiel, H., Hempel,
         K. J. & Merkle, J. Two-year feeding test with Kollidon 25 in
         rats. Unpublished report from BASF Gewerbehygiene and
         Toxikologie, Ludwigshafen, Rhein, FRG. Submitted to the World
         Health Organization by BASF, 1969

    Zendzion, R. P. & Teeter, W. R. Tests intravenous administration of
         PVP in beagle dogs. Unpublished report from Hazleton Laboratories
    


    See Also:
       Toxicological Abbreviations