The Bactericidal and Antiseptic Action of Preservatives Frequently Used in Biological Products, and the Effect of These Preservatives on the Potencies of the Products*

Paraben Compounds—Part I: An Overview of Their Characteristics, Detection, and Impacts

“…Additionally, contrary to what happened for PP, for MP no differences were observed in the labeling index in the prefundic area of forestomach epithelium of rats [21]. However, and although the conclusion of the test was that MP was not carcinogenic, some experiments in rats allowed an incidence of 1.5% for injection-site tumors (fibrosarcomas) compared to control [21,80]. For other studies, in tumors that appeared in rats treated with MP, only mammary fibroadenoma was higher than negative controls (8% and 1%, respectively), and the incidence of injection-site tumors, pituitary adenomas, uterine polyps and leukemias did not had a different incidence compared to controls [21,80].…”

“…However, and although the conclusion of the test was that MP was not carcinogenic, some experiments in rats allowed an incidence of 1.5% for injection-site tumors (fibrosarcomas) compared to control [21,80]. For other studies, in tumors that appeared in rats treated with MP, only mammary fibroadenoma was higher than negative controls (8% and 1%, respectively), and the incidence of injection-site tumors, pituitary adenomas, uterine polyps and leukemias did not had a different incidence compared to controls [21,80]. However, in general, the studies concluded that methylparaben is not carcinogenic for rats and mice, and for other studies in rats, mice, hamsters, and rabbits it was concluded that MP is not embryotoxic or teratogenic [21,81,82].…”

The Influence of the Recovery Medium and the Incubation Temperature on the Survival of Damaged Bacteria

“…Stapleton, Billen & Hollaender (1953), however, found no difference between agar and liquid media for the recovery of X-irradiated E. coli strain Sir. Rosenstein & Levin (1935) observed that all three types of response to agar (better, poorer, no difference) may occur, and it is possible that some of this conflict of evidence regarding the value of agar derives from the variable performance of this substance (Jacobs & Harris, 1961), especially when derived from different geographical sources or when it is used in the cultivation of a number of different species, damaged by a variety of agents (Harris & Richards, to be published).…”

A Comparative Study of the Use of Varying Concentrations of Agar in the Test Medium Used to Detect Contaminants in Biologic Products

“…The media containing from one to 0.001 parts of agar per hundred were prepared by diluting 2 per cent biologicproducts agar with sufficient biologic-products broth (containing 0.03 per cent glucose) so that the desired concentrations of agar were obtained. The method of preparing these basic media has been described in previous papers (Rosenstein and Levin, 1935;Falk and Appington, 1936). The media, made up in 300 cc.…”

“…Previous reports on the bactericidal action of antiseptics used in biologic products (Rosenstein and Levin, 1935;Falk and Aplington, 1936) showed that, when a given organism was inoculated into both broth and agar media, growth sometimes appeared in the agar and not in the broth and vice-versa. These findings could not be attributed to bacteriostatic action caused by insufficient dilution of the antiseptic present, since identical results were at times obtained in the control tubes containing no antiseptic.…”