A Novel Improved Bioburden Recovery Method Using Swabbing Technique

The validation of surface-recovery methods is a pre-requisite for residual determination of cleaning effectiveness in process validation studies. These methods should be challenged in the laboratory using pilot-scale controlled conditions in order to evaluate the suitability for their intended use. Different swabbing techniques have been studied and compared with rinse method for 7 microorganisms (Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Kocuria rosea, Candida albicans and Aspergillus niger) on 5 different coupon surfaces (Stainless steel, Glass, Rubber, TEFLON and Plexiglass) representing machine materials in production area. Only one swabbing technique gave good results in comparison to both rinsing method and previously reported NylonTM flocked QUANTISWABTM. The new swabbing technique is based on ordinary RayonTM fiber which is known of low microbial recovery using traditional method. However simple modification in the recovery procedure using simple device improved the bioburden recovery to become over 80%. Moreover this novel method has good flexibility to be customized to enhance recovery according to cleaning validation condition and study.