Polidronium Chloride is a biocide agent which can be used as a preservative, unique in its high safety profile. Polidronium Chloride is a polycationic preservative that, unlike benzalkonium chloride, does not have detergent properties. This agent complies with both the US and European Pharmacopeia guidelines for preservative efficacy. Polidronium Chloride is a large molecule that preferentially targets microorganisms and produces minimal toxicity towards mammalian cells. Polidronium Chloride compares favorably to other preservatives in terms of efficacy. Published studies demonstrate that this preservative, added to contact lens solutions, artificial tears, and ocular hypotensive drops may offer benefits in terms of ocular tolerability compared to benzalkonium chloride. Polidronium Chloride is comparable in tolerability to other alternative preservatives such as sodium perborate, Purite. Therefore, Polidronium Chloride may be considered as a viable alternative to benzalkonium chloride for many topical ophthalmic formulations.Polidronium Chloride prepared by the controlled polymerization of dimethylamine and bis-dichlorobutene, end capped with tris-beta-hydroxyethylamine.