SBIR-STTR Award

Catheter associated urinary tract infection (CAUTI) remains a significant problem, being the most common nosocomial infection acquired in hospitals. The goal of this program is the fabrication and evaluation of a new medicated urinary catheter manufactured from a silicone rubber material which is loaded with the antimicrobial agent chlorhexidine gluconate (CHG). This material has previously been shown to be effective against organisms typically encountered with CAUTI. The CHG is contained in a polyethylene glycol matrix uniformly dispersed in the elastomer and designed to release the drug over a period of up to 4 weeks. The choice of CHG as the antimicrobial agent is based on its broad spectrum activity, low incidence of the development of bacterial resistance to its action, and its comparatively low toxicity. Catheters with 1%, 2%, 3%, and 4% CHG by weight will be fabricated by compression molding and also by a modified form of injection molding. The release of CHG from the catheters will be quantitated in vitro over a 4 week period using high performance liquid chromatography. Test specimens of each candidate formulation will then be evaluated for their potential as mucosal irritants in an adult rabbit animal model for a 7 day period of contact. The aim of this medicated catheter system is to inhibit or prevent biofilm formation on either the luminal or tissue facing catheter surfaces, a situation which makes CAUTI very difficult to treat. Following biofilm formation, antibiotic concentrations ranging from 500-5,000 times that required to kill free floating organisms of the same species are needed. PROPOSED COMMERCIAL APPLICATIONS: A urinary catheter that effectively inhibits bacterial growth has the potential to significantly improve care for patients undergoing a wide variety of surgical procedures. The new urinary catheter has the potential to reduce hospital costs associated with the management of catheter associated infections.

Catheter-associated urinary tract infection (UTIc) is the most common nosocomial infection acquired in hospitals and nursing homes. The goal of this Phase II program is to continue the development and evaluation of a new, drug releasing urinary catheter fabricated from silicone rubber containing the antiseptic agent chlorhexidine gluconate (CHG). The CHG is confined in a polyethylene glycol matrix uniformly dispersed in the elastomer, and it is released in sustained fashion over periods up to 4 weeks. This catheter material has been shown to be effective in vitro against organisms commonly associated with UTI. The choice of CHG as the antiseptic agent is based on its broad spectrum of activity, comparatively low toxicity, and low incidence of the development of bacterial resistance. In Phase II, methods for fabricating the catheters will be refined, and the effectiveness of the catheter material to inhibit or kill bacteria as a function of usage time evaluated. Toxicity studies required to fulfill the requirements of ISO 10993-18, a standard for medical device materials, will be conducted; and the shelf life of the catheters will be determined. Finally, a double blind, randomized trial of drug releasing versus nondrug releasing catheters in a large animal model will be conducted to measure efficacy in lessening or preventing the development of UTIc or pylonephritis over a 28 day period.

Thesaurus Terms:
antibiotic, biomaterial development /preparation, biomedical equipment development, chlorhexidine, drug delivery system, silicone rubber, urinary catheterization, urinary tract infection antisepsis, biofilm, biomaterial compatibility, elastomer, gluconate, molecular film, slow release drug cow, high performance liquid chromatography