Radiation sterilization of medical products in the Philippines

Abstract

This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. Hence, the materials used were directly obtained from local manufacturers. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis . The D 10 values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged. These studies indicated that radiation sterilization is technically feasible for locally manufactured medical products.