Silver Ion Antimicrobial Agents in the Battle Against Hospital Acquired Infections

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1 Silver Ion Antimicrobial Agents in the Battle Against Hospital Acquired Infections MD&M East Innovation Briefs Session, June 8, 2011 Presented By: Philip A. Dix Medical Marketing & Development Manager LTL Color Compounders, Inc.

2 LTL Color Compounders Color & additive compounder in its 21st year Located in Morrisville, PA and Dongguan, China Work with essentially all thermoplastic resins No minimum order size Proprietary product lines: ColorRx, ColorFast, EcoFast, Surlyn Reflection Series * Official compounder of Avaspire ** PAEK resin Custom and toll compounding in resin grades specified by the customer Certified to ISO 9001 and ISO (for ColorRx medical grades) * Registered trademark of E.I. Dupont ** Registered trademark of Solvay Advanced Polymers

3 Why the Concern over HAI s? Equipment and device surfaces breed bacteria Common examples of HAI s: ventilator-acquired pneumonia, bloodstream infections, urinary tract infections, and surgical site infections The CDC* estimated in 2002 there were 1.7 M cases of HAI s per year and 99,000 deaths A 2005 survey by APIC** estimated 1.2M cases per year of MRSA alone with k deaths The CDC estimated in 2007 the cost of treating HAI s at $28-35 billion. After 2008 Medicare stopped reimbursing hospitals for treating HAI s * Centers for Disease Control & Prevention ** Association for Professionals in Infection Control & Epidemiology

4 Silver in the Arsenal of HAI Prevention Methods Long history of use from ancient through modern times (e.g. silver coins in water, silver nitrate) Very effective at inhibiting bacterial growth on surfaces. Silver is the most effective metal ion. Examples where now used: catheters, IV tubing and components, infusion tubing, urinary tract devices, wound care, durable items. A valuable component of a comprehensive HAI management system that includes personnel hygiene and equipment / surface sanitization.

5 Mechanism of Activity of Silver Ion AM s Ionic silver, bound in an inorganic matrix, is incorporated throughout the plastic resin. Silver ions elute to the surface of a plastic article in the presence of trace amounts of moisture. Due to the reservoir of silver ions in the plastic effectiveness is maintained for long periods. Silver binds to the surface of a microorganism where it bursts the cell wall or is transported into the cell. Once inside the cell, silver ions do the following: Incapacitate the cell s energy generation mechanism Disrupt the cell s DNA replication As a result cells fail to replicate. The effect is seen over a period of hours

6 Typical Efficacy Results LTL sample plaques tested against JIS Z JIS Z 2801 measures reduction in bacterial count of S. aureus and E. coli on a plaque surface after 24 hours. % Reduction* results with as little as 0.5% AM: * Treated plaque compared to untreated plaque Resin PC ABS HDPE PP E. coli > > > 99.6 > 99.6 S. aureus > > > 99.8 > 99.9

7 Efficacy, cont d Silver ion AM s should be part of an HAI control plan that includes surface sanitizing agents such as bleach. Question: Will chlorine bleach effect silver AM? Results of lab study (% Reduction): Resin ABS ABS soaked in bleach for 16 hrs ABS soaked in bleach for 24 hrs E. coli > > S. aureus > > >

8 Longevity of Silver Ion AM Silver ions elute in the presence of moisture Question: How does the efficacy hold up over long periods of time? The Society of Industrial Technology for Antimicrobial Articles (Japan) has defined a 16 hour, 25C water soak test to simulate 5 years. LTL tests in ABS show > % reduction for E. coli and > % for S. aureus after the soak.

9 Advantages of Silver Ion AM Safety: Low Toxicity, Long History of Use Longevity Compounded throughout the material Elutes gradually and continuously i.e. Silver ions are self-replenishing at the surface Not effected by surface wear or dirt Adaptable to all resin types and processing methods (not degraded at typical proc. temps.) Maintains physical & mechanical properties Maintains clarity in transparent resins Organisms do not develop immunity Cost effective

10 Silver Ion AM Toxicity Acute oral toxicity > 5000 mg/kg in mice Not a skin irritant or sensitizer Not a mutagenic agent

11 Regulatory Issues for Silver Ion AM s AM s are regulated by the EPA under FIFRA. If approved by FDA in a medical device, this approval trumps EPA. If not used in an FDA regulated application the OEM must either: Obtain approval from EPA for each specific end use. Requires extensive data and a lengthy approval process. Market under the EPA exemption for AM s which allows only claims that the product itself is protected from odor, discoloration, or degradation. No human health claims can be made or implied.

12 Conclusion Silver ion antimicrobial agents are a valuable tool in the arsenal of HAI countermeasures and should be used to complement other methods such as improved personnel hygiene and equipment sanitization.