A machine used for making medicines cannot simply be installed and started for production. Before that happens, the pharma company has to know whether the equipment is right for the work. Is it installed properly? Does it work as expected? And can it continue doing the same job without problems?
This is where DQ, IQ, OQ and PQ are used. These are four stages of qualification followed for equipment and systems used in pharmaceutical manufacturing.
The names may sound a little technical. But what they actually mean is not too difficult to understand. Each one checks the equipment at a different point.
What Is DQ in Pharma?
DQ stands for Design Qualification. This usually happens before the equipment is purchased and installed.
Here, the proposed design is checked first. The company basically wants to know whether the equipment being considered is suitable for the work it needs to do.
Take a tablet compression machine, for example. Before buying one, the company has to look at its capacity, construction materials, controls, safety features and cleaning needs. Other specifications are checked as well.
DQ may include:
- Equipment design and specifications
- Materials used for construction
- Production capacity
- Cleaning and maintenance needs
- Safety features
- GMP requirements
Why do this so early? Because discovering a problem with the design after buying and installing the machine can become expensive. It can also delay the work.
What Is IQ in Pharma?
IQ means Installation Qualification.
Now the equipment has arrived and has been installed. The next job is to check whether that installation has been done properly.
The team checks the machine against the approved specifications, drawings and instructions given by the manufacturer. This is more than just checking whether the machine is sitting in the correct place.
Electrical connections may need checking. The same goes for utilities, machine parts, instruments, manuals and calibration records.
For example, think about a filling machine. During IQ, the team checks whether the necessary parts are available and fitted correctly. Connections are checked too. Instruments that need calibration should also have the required records.
So, IQ is really asking one thing: “Was the equipment installed correctly?”
What Is OQ in Pharma?
OQ stands for Operational Qualification.
Once the installation has been checked, attention moves to the way the equipment actually works.
During OQ, the machine is operated and tested under defined conditions. The purpose is to find out whether it works within the required operating range.
Controls, alarms, switches and safety systems may all be checked. Different operating settings can also be tested. In some cases, testing is done near the upper and lower limits of the operating range.
For example, consider equipment that needs to maintain a certain temperature. It may be run at different settings to see whether the controls work and the required temperature can be maintained.
DQ vs IQ vs OQ vs PQ
Here is an easy way to remember the difference:
| Stage | Full Form | What It Checks |
| DQ | Design Qualification | Is the design suitable? |
| IQ | Installation Qualification | Is it installed correctly? |
| OQ | Operational Qualification | Does it operate correctly? |
| PQ | Performance Qualification | Does it perform consistently? |
What Is PQ in Pharma?
PQ means Performance Qualification.
By now, the equipment has already gone through installation and operational checks. But one more question remains. Can it keep doing its intended job properly during regular use?
That is what PQ looks at.
The equipment is run under normal or defined production conditions. Approved procedures and materials may be used, along with trained staff. The results are then checked to see whether the expected performance is achieved again and again.
A tablet compression machine, for instance, may be operated under set production conditions. The tablets made during these runs can then be checked against the required quality specifications.
Conclusion
DQ, IQ, OQ and PQ are easier to understand when looked at one by one. DQ checks whether the design is suitable. IQ checks the installation. OQ checks whether the equipment operates correctly. PQ looks at whether it performs consistently during use.
All four checks have their own role. Together, they help a pharma company know that the equipment is suitable for the work before it becomes part of regular production.