Sterilizing Bacillus pumilus spores using supercritical carbon dioxide

Solvent Removal and Spore Inactivation Directly in Dispensing Vials with Supercritical Carbon Dioxide and Sterilant

“…Consistent with the findings of White et al (9) and Zhang et al, (10) elevating the temperature to 50°C and/or extending the exposure time to 4 h had no effect on survival of spores of all three BI. In each case the log reduction was less than 1 (data not shown).…”

“…We deliberately used less rigorous scCO 2 conditions (lower pressure, lower temperature, and shorter times) than previous investigators (7)(8)(9)(10) who also demonstrated spore killing at a log reduction level of 6 so that we might minimize any potentially deleterious effects on drug substance. In our hands, and under the conditions used, B. pumilus proved to be the most resistant of the three microorganisms tested, whereas B. atrophaeus and G. stearothermophilus tended to show less, but equal susceptibility.…”

“…While a certain degree of success is obtained with scCO 2 against vegetative forms of several common food contaminants, it was not until recently that methods were described to achieve the sterility assurance level (SAL) of 10 against the difficulty to sterilize spore-forming bacteria that is necessary to produce safe injectable drugs. Several laboratories reported that it is possible to achieve a SAL of 10 −6 against dry spores using scCO 2 with added sterilants (7)(8)(9)(10). These laboratories reported successful destruction of spores using scCO 2 at pressures ranging from 10.34 to 30.34 MPa (1,500 to 4,400 psi), temperatures ranging from 34 to 80°C and for exposure times between 30 min and 4 h.…”

Supercritical carbon dioxide and hydrogen peroxide cause mild changes in spore structures associated with high killing rate of Bacillus anthracis

“…As a result, a high degree of reduction of viable spores (up to 6.14 log reduction) has been observed, confirming the sporicidal effects of this mixture at low temperatures for spores of other bacilli (Hemmer, Drews, LaBerge andMatthews, 2006, Zhang, Burrows, Matthews, Drews, LaBerge and. This degree of log reduction meets the sterilization requirement set by the FDA.…”

Mutation breeding of lipase-producing strain Flavobacterium sp. by supercritical CO2 with hydrazine hydrate

“…CO 2 is frequently used in near-, or supercritical conditions, wherein it shows excellent mass transfer properties in terms of penetration into matrices (Valverde et al 2010). Possibly due to assist in the permeability, supercritical CO 2 had been found to enhance the sterilization effects and/or mutagenicity of the additives (co-solvents) such as hydrogen peroxide (H 2 O 2 ) (Zhang et al 2006), dimethylsulfoxide (DMSO) (Zhang et al 2008), etc. The solvent properties of supercritical CO 2 could also be drastically changed by the addition of a small amount of polar solvent as a modifier (Sicardi et al 2000).…”