In Vivo Evaluations of a Novel Alcohol-Based Hand Rub, MR09B10.

BACKGROUND: Alcohol-based hand rubs (ABHRs), common in many clinical settings provide microbicidal activity and have been formulated as liquids, gels and foams to increase compliance of hand hygiene. MR09B10 has been developed as a non-aerosol foam ABHR containing 83% ethanol and 0.2% Chlorhexidine Gluconate for the first time ever in Japan. OBJECTIVES: To investigate the effectiveness of MR09B10 through in vivo antimicrobial evaluation tests. METHODS: In vivo effectiveness was investigated using the palm stamp and glove juice methods. The palm stamp method was conducted by taking the imprints of each volunteer’s hands before (baseline) and within 1 minute to assess the immediate effect of MR09B10. A Japanese quasi drug and 83% ethanol were used as reference drugs. Each participant’s palm was pressed for 5 seconds onto a soybean case with digest agar plates. After incubation, bacterial reduction from baseline was calculated using the number of surviving bacteria. The glove juice method was then conducted according to the methodology of ASTM E 1174, as specified by the TFM for Effectiveness Testing of an Antiseptic Hand wash or Health Care Personnel Handwash Products. Seventeen subjects tested MR09B10 over the course of 11 consecutive hand contaminations. The first assessment was followed by taking a sample for baseline and the remaining 10 via product applications using microbial samples taken after product applications 1 and 10. RESULTS: The Palm Test results indicated that MR09B10 has the same effectiveness as the reference drug 83% ethanol. The Japanese quasi drug did not achieve the same efficacy as MR09B10 or 83% ethanol. Using the glove juice test, MR09B10 produced a mean log10 reduction of Serratia marcescens of 2.62 after 1 application and 3.58 after 10 applications. Therefore, MR09B10 achieved log reductions of greater than 2 after application 1 and greater than 3 after application 10 and it also satisfied critical indices of the 1994 FDA TFM. CONCLUSIONS: The palm stamp method is one of the most popular test methods to evaluate bactericidal activity against transient flora on hands and it has been performed in Japanese clinical settings to further promote and highlight the importance of hand hygiene. ABHRs that have sufficient efficacy and satisfy the 1994 FDA TFM critical indices are becoming the standard for infection control in Japan. These findings suggest that MR09B10 has satisfied both standards. Yakugaku Zasshi. 2010;130(5):747-754.