Experimental carcinogenic studies in macromolecular chemicals. I. Neoplastic reactions in rats and mice after parenteral introduction of polyvinyl pyrrolidones

Final Report On the Safety Assessment of Polyvinylpyrrolidone (PVP)

Polyvinylpyrrolidone (PVP) is a linear polymer of 1-vinyl-2-pyrrolidone monomers used as a binder, emulsion stabilizer, film former, hair fixative, and suspending agent-nonsurfactant. The molecular weight of the polymer ranges from 10,000 to 700,000. PVP K-30, with an average molecular weight of 40,000, is typically used in cosmetic formulations. The highest concentration reported to be used is 35%. There was no significant absorption of PVP K-30 given orally to rats, and the acute oral LD50 was >100 g/kg for rats and guinea pigs. Neither toxic effects nor gross lesions were found in rats maintained for two years on a diet containing 10% PVP K-30. Short-term PVP inhalation studies produced mild lymphoid hyperplasia and fibroplasia in rats, but no inflammatory response. In animal studies, no evidence of significant ocular irritation, skin irritation, or skin sensitization was found at PVP-iodine solution concentrations of 10%. While PVP-iodine is not a cosmetic ingredient, these negative findings were considered to support the safety of the PVP component. Undiluted PVP K-30 was not a dermal irritant or sensitizer in clinical tests. No developmental toxicity was seen in vehicle controls where PVP was used as a vehicle for another agent. In certain assay systems, PVP was genotoxic, but was negative in the majority of studies. Orally administered PVP significantly decreased the rate of bladder tumors in mice exposed to bracken fern. Several studies tested the carcinogenicity of subcutaneous implants of particulate PVP in rats, mice, and rabbits. Although the majority of these studies conducted in rats were positive, tumors (sarcomas) were localized to the site of implantation. Based on the available data, it was concluded that PVP is safe as used in cosmetics.

Origins of injection-site sarcomas in cats: the possible role of chronic inflammation-a review

The etiology of feline injection-site sarcomas remains obscure. Sarcomas and other tumors are known to be associated with viral infections in humans and other animals, including cats. However, the available evidence suggests that this is not the case with feline injection-site sarcomas. These tumors have more in common with sarcomas noted in experimental studies with laboratory animals where foreign materials such as glass, plastics, and metal are the causal agent. Tumors arising with these agents are associated with chronic inflammation at the injection or implantation sites. Similar tumors have been observed, albeit infrequently, at microchip implantation sites, and these also are associated with chronic inflammation. It is suggested that injection-site sarcomas in cats may arise at the administration site as a result of chronic inflammation, possibly provoked by adjuvant materials, with subsequent DNA damage, cellular transformation, and clonal expansion. However, more fundamental research is required to elucidate the mechanisms involved.