How to Identify Swab Sampling Locations for Cleaning Validation

RIBOFLAVIN CHALLENGE STUDY  

Contact parts of the equipment, used for the manufacturing of any product may have risk to carry the residue of product over to next product if not cleaned properly. So, suitable cleaning procedure applies to remove the residues of previous product form all surfaces of equipment. So for ensure the efficiency of cleaning procedure validation of the same is required to be carried out.

During collection of samples for Cleaning Validation it is not possible to take samples from entire surface of the equipment, hence representative samples are collected from the some locations only. Often selection of such sampling location are based on the experience and visually observed hard to clean area.

Once the cleaning validation sample passed for such location it is considered that the entire equipment is passing in cleaning validation. But as this locations are considered based on the experience or visual observation, there may be chances that if due to error any hard to clean area is not identified it may leads to cross contamination in the product. 

So to overcome this problem Riboflavin Challenge Study can be performed to identify the hard to clean area which is an accurate method rather than experience or visual selection. 

RATIONALE OF RIBOFLAVIN CHALLENGE  

Riboflavin is a highly fluorescent molecule and when exposed to ultra violet (UV) light, it produce fluorescence. This helps is detection of any traces remaining after cleaning of surface previously exposed with Riboflavin. To increase the adherence of Riboflavin to the equipment surface, Carboxymethylecellulose (CMC) is added in the Riboflavin Solution which makes the solution sticky and help to increase the adherence of Riboflavin. 

The places where Riboflavin traces are detected after cleaning are to be considered as hard to clean parts for cleaning and should be incorporated in cleaning validation for swab sample collection points. 

PROCEDURE 

Precautions while using UV Light

• Wear UV protected safety eye glasses and do not look directly into the UV Light.
• Do not let the skin or any body part come directly in the contact of UV Light.

Preparation of Riboflavin Solution  

• Add slowly  10 gm of Carboxymethylecellulose to hot 1 litre of purified water with vigorous stirring to make liquid slurry. 
• Add slowly 2 gm of Riboflavin to this slurry and mix thoroughly. 

Application of Riboflavin Solution to the Equipment

• Spray the Riboflavin solution evenly to the entire product contact surface area of the equipment, dismantle parts and let the spray to be dry for at least 4 hours.
• Verify the uniformity of the Riboflavin by using the UV light and take photographs.

Cleaning of the Riboflavin Solution

• Wash the equipment and dismantle parts as per respective Standard Operating Procedure by using Half Cycle Method (Half time of the washing period mentioned in the SOP).

Identification of Hard to Clean Parts

• Verify the presence of Riboflavin on the surface of equipment and dismantle parts by using the UV Light and take photographs. 
• Areas of equipment and dismantle parts which are having more Riboflavin stains shall be identified as hard to clan areas. Such areas shall be considered for locations for swab samples during Cleaning Validation. 

Conclusion 

So based on the Riboflavin challenge study we can identify hard to clean areas for the location to collect the swabs for cleaning validation with more accuracy and scientific method rather than experience or visual observations. 

So friends that all for the day, Thanks for reading and please share if you have liked this blog. Please do let me know in comment if you have any query...