How to Use TOC Cleaning Verification Swabs

Cleaning validation is a process that requires complete documentation to prove that the cleaning of production facilities in the pharmaceutical industry is effective and consistent. This article will describe the use of TOC cleaning validation swabs.

Tools / Materials

Sterile sampling swabs, markers, sample bottles, sampling labels, etc.

Methods for Using TOC Cleaning Verification Swabs

Step 1

Tear the sealing paper on the packing tape of the TOC swab and gently remove the sampling swab from the bag, taking care that the mouth of the sampling head does not touch other items other than the sampling sample to avoid contamination.

Step 2

1: Wipe the area so that the amount of residue in line with the linear range of the test method. It is usually advisable to 25cm2 or 100cm2 determine the wipe solvent and swab, specify the degree of swab wetting. If the swab is moistened and squeezed on the solvent bottle until no drips are collected from certain areas inside the pharmaceutical production tank. These areas can be the inner wall of the tank or a small plate called a “sample” (during the production process, this plate is suspended on the surface of the product as a marker of the cleanliness and cleaning of the production tank). A swab is placed on the surface to be sampled, and the entire surface of the sample is wiped. The direction and pressure of the wipe are defined in the cleaning standard operating procedure (SOP).

2: To wipe, press the swab tip onto the sampling surface and apply pressure to bend it at 45° to the wiping surface. Smoothly and slowly wipe the sampling surface, moving it from one side to the other while moving forward. The wiping process should cover the entire surface. (Flip the swab so that the other side of the swab is also wiped, but perpendicular to the previous wipe moving direction, each swab is wiped to sample 25 cm² respectively. The sampling location should avoid duplication with the microbial sampling point).

After wiping, each sampling point’s swab tip was cut off, put into the same sample receiving tube, and sealed with a stopper.

Step 3:

This sampled swab is then extracted. The swab is placed in a vial containing an acidic solution, followed by an ultrasonic or centrifugal process, and finally, the TOC concentration of this acidic solution is analyzed. The swab can also be analyzed by placing it in a sealed glass ampoule containing 5% phosphoric acid and 100 g/l sodium persulfate solution. The carbon dioxide in the form of inorganic carbon is purged into the environment, and the glass vial is then sealed. The glass vial is heated to 100°C and stored for the specified time. Eventually, the glass vial is opened, and the TOC is blown out as carbon dioxide and assayed.

esidues.