Pharmaceutical and biopharmaceutical manufacturers use many kind of reactors, vessels, pipelines which are exposed to the product directly and cleanliness of the same is greatly impacted on the proceeding batch product quality. These process equipment are either glass lined or electro-polished to ensure the smooth surface and also inert to the reactions. It is also fact that the same assembly of process equipment are also used for many batches of different kind of chemical combinations.
| Residue found in the shaft of the spray ball | Inspecting an inlet line fitted with globe valve |
Ensuring right equipment and optimum level of cleanliness is the key to get a higher product quality. Maintaining product quality through contamination control is very much important. It is also important to clean the vessel before use for the next batch to ensure zero cross contamination. Cleaning processes are one of the primary means of contamination control between production batches. Generally the reactors and the pipelines are cleaned with water, detergents, WFI etc. The process of cleaning is decided based on the chemical characteristic of the previous batch (last batch) ingredients.
| A visually cleaned surface of a glass lined reactor | Pan-Tilt-Zoom Cameras (PTZ) |
The cleaning cycle to be developed should take the following into consideration
- Surfactant concentration
- Solvent / water
- Time
- Temperature
- Imparted mechanical Energy
- Developing a proper mix of the above will ensure the equipment are clean enough to use for the next production batch. Once the SOP of cleaning is laid down it has to be validated and periodically verified by
- Visual inspection
- Analytical Testing (HPLC/ TOC)
Both the above steps have to be performed and documented to certify the cleaning process is good enough to clean all the residue of the last batch. These process are very much dependent of the person who does it. In case of visual inspection it is very much dependent on the person at the same time documenting is also an issue. There are few other difficulties / hassles are there in term of personal safety and health hazard. These activities owe for a confined space entry clearance from the EHS and need to take prior precaution and documentation before we send a person for the job. So it is always point of discussion whether to do that or not and decided to skip and follow only the analytical testing.
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Video Borescope Inspections
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The analytical testing will definitely find out the residue more in micro level but fail to identify the cleanness at the places which is difficult to reach and which might be a place where even the washing might not reached.
To eliminate all the ifs and buts it is advisable to use a camera which take the picture of the critical surfaces which are hard/difficult to reach, it help to document the visual inspection process. These cameras should have extended arms which can be put inside the vessels or pipes and take pictures at most difficult or complex structures which should be defined in SOP based on the vessels shape, size and utilities fitted in it. once the camera is being sent inside it should be articulated in every direction to get picture of different surfaces to ensure the cleanliness uniformity. The all pictures or videos should be kept along with the validation document.
So using such camera will eliminate the risk of non compliance, downtime and unnecessary EHS documentation hassles and provide high degree of assurance of the cleaning process. Remote Visual Inspection (RVI) procedures using video borescopes and Pan-Tilt-Zoom (PTZ) cameras provide an alternative to costly disassembly procedures or confined space inspections which are time-consuming and hazardous due to life-risk associated with entry into hazardous locations.
Pan-Tilt-Zoom Cameras (PTZ)
| Value story for use of video inspection equipment |
PTZ cameras offer the greatest flexibility for large tank inspection. With integrated lighting and an optical zoom capability of up to 36X, PTZ cameras can be lowered into reactor vessels and be remotely controlled to perform a full tank inspection. PTZ camera systems include a camera Controller Unit (CCU) which is capable of capturing still images or motion video. An accessory laser measurement system allows defect measurements to be performed on target inspection areas based upon known spacing of the projected laser targets.
PTZ camera systems can also be fitted with UV filters to allow CIP (Clean-In-Place) inspections using a Riboflavin Rinse technique prior to activation of a tank cleaning spray-ball. The source of the UV light can either be an integrated PTZ light source or a secondary UV illumination source, video borescope Inspections
Traditionally, video borescopes have not been used to perform general tank inspections – primarily based on the large distances and surface areas required to be inspected. Video borescopes are best suited to perform specialised inspections, such as inspecting the seal integrity of a reactor vessel, or the efficiency of the cleaning process around the top-cover penetrations. When used in conjunction with guide tubes, a video borescope can generally be directed to inspect any area of a vessel. In the past, if a video borescope needed to inspect at distances exceeding 12 inches, or even closer when using high-magnification optical tip adapters, the inspection image was very dark. Modern video borescopes now offer a ‘Long Exposure’ mode of operation whereby the CCD imager collects image signals for a longer period of time resulting in a brighter, crisper image.
The use of video inspection equipment assists in identifying potential problems associated with incomplete vessel cleaning or damaged seals can easily cost-justify the investment in video inspection equipment. If it was found at a later time that a vessel was in fact improperly cleaned, up to $100,000 per month of product may be required to be scrapped. If product manufactured in contaminated vessels was shipped into the commercial distribution channels, a product recall, potentially costing millions of dollars may be required.
(The author can be reached at rsahu@skytechindia.com)