[Use of ionizing radiation for sterilizing alginate dressings containing various antibacterial preparations]

The effect of various doses of ionizing radiation on activity of antibacterial drugs contained in polymer alginate coatings was studied. Sensitivity of P. aeruginosa, E. coli, Staph. aureus, Proteus and B. subtilis used as the test organisms to the drugs and their combinations after radiation sterilization was determined on liquid nutrient media with the method of serial dilutions and agar diffusion and the use of the respective reference antibiotics. The coatings were irradiated in an isotope unit with 60Co at a dose of 7 Krad/min. The data are indicative of the possible use of ionizing radiation for sterilization of pharmaceutical alginate coatings in trade packings. Combined effect of antimicrobial substances and ionizing radiation plays an important role in the efficiency of radiation sterilization. Sterility of the majority of the drugs was achieved after irradiation in doses of 0.5-1 Mrad. The bactericidal activity of gentamicin, mafenid, polymyxin M and neomycin contained in the alginate coatings sterilized with gamma-radiation in doses of 1-2.5 Mrad did not decrease immediately and 1 year after irradiation.