LoxaSperse is a powder excipient base used for nebulization and irrigation. LoxaSperse is a blend of specially micronized xylitol with an optimized ratio of micronized poloxamers, designed to improve the dispersability and solubility of APIs (PCCA, 2013). The use of xylitol and poloxamers in nebulization and irrigation is thoroughly referenced in the literature and there is ample evidence of their safety and efficacy (Durairaj et al., 2006; Jagannath et al., 1995; Plataki et al., 2011; Zabner et al., 2000). Gentamicin is an aminoglycoside antibiotic and has bactericidal action against many gram-negative aerobes and against strains of staphylococci (Martindale 35, 2007). PCCA tested the performance of Formula #10337 which is gentamicin (80 mg) in a LoxaSperse mixture and measured efficacy against microbial activity when mixed with sterile water.
LoxaSperse is a powder excipient base used for nebulization and irrigation designed to improve dispersibility and solubility of Active Pharmaceutical Ingredients (APIs). PCCA tested the performance of PCCA Formula #10337 (gentamicin 80 mg/LoxaSperse), and measured its efficacy against microbial activity when mixed with sterile water. The Antimicrobial Effectiveness Test (AET) was conducted at 0.5h, 6h, 28h and 168h – serially diluted, and plated for colony counts. Gentamicin LoxaSperse dispersions reduced the number of viable bacteria (E. coli, S. aureus and P. aeruginosa) within 0.5h of exposure and no bacterial growth was observed in the test article up to 128h after exposure. A 3-Log to 4-Log reduction in viable bacterial cells was observed within 0.5h.
The Test Article containing Gentamicin Sulfate USP reduced the number of viable bacteria (E. coli, S. aureus and P. aeruginosa) within 0.5h of exposure and no bacterial growth was observed up to 168 h after exposure. A 3-Log to 4-Log reduction in viable bacteria was observed within 0.5h (Tables 1-2). A 1-Log reduction in the number of viable C. albicans cells was observed within 6h and no C. albicans cells were recovered after 24h (a 2-Log reduction). The gentamicin formulation continued to reduce the number of viable A. niger spores throughout testing.
Additionally, the low number of spores introduced at the initiation of the AET and the subsequent low limit of detection prevented the observation of a significant 1-Log reduction of viable spores.