[Evaluation of usability of an anticancer drug after changing it to liquid formulation].

Although the advantages of a liquid formulation over a lyophilized one have been mentioned, few studies have quantified the differences between the two. For the purpose of clarifying the advantages of a liquid formulation, we carried out a comparison of ELPLAT I. V. INFUSION SOLUTION, which is a liquid formulation of oxaliplatin, and ELPLAT FOR INJECTION, which is a lyophilized formulation of oxaliplatin. Since multiple factors(such as skill in drug preparation and the dosage)as well as the formulation influenced the preparation time, each factor was assessed by a Latin square design. The mean preparation time was 62. 39 seconds for the liquid formulation and 171. 22 seconds for the lyophilized formulation, and a decrease of approximately two minutes(p<0. 0001)was observed with the liquid formulation. Furthermore, after linear regression analysis of multiple factors, shortening of the preparation time was found to be related to the liquid formulation. The preparation time was significantly shortened according to the level of skill in drug preparation with the liquid formulation, but not the lyophilized formulation. This was because the total preparation time was relatively long for the lyophilized formulation. Superior usability of liquid formulation was shown by our quantification of the advantages of liquid oxaliplatin.

Novel endotoxin assay by laser light-scattering particle-counting method.

Exposure of Limulus amoebocyte lysate to endotoxin under stirring produced light-reflective particles that appeared to be coagulin polymers. A laser light-scattering particle counter, the PA-200, detected these particles sensitively. The PA-200 detected endotoxin at a concentration as low as 0.00015 EU/ml in 71 min, whereas the minimum endotoxin concentration measured by a turbidimeter, ET-2000, was 0.0005 EU/ml in 138 min. Moreover, PA-200 was much less affected by the presence of colored substances and refractive materials than was ET-2000. We propose that the high sensitivity, speed, and high interference tolerance of the laser light-scattering particle-counting method make it more useful than the widely used turbidimetric method for quantitative endotoxin assay.