Quality Assurance, Quality Control and Good Manufacturing Practice
9 minute read
What you will learn
- Define quality assurance, quality control and GMP and show how they relate
- List the main areas covered by GMP
- Explain the importance of documentation and batch records
- Describe in-process and final quality control
- Explain complaints, recalls and self-inspection
- Calculate a simple production yield and a percentage of label claim
Key points
- Quality assurance (QA) is the whole system that makes sure medicines are of the right quality for their intended use.
- Good Manufacturing Practice (GMP) is the part of QA that ensures products are consistently made and controlled to the required standards.
- Quality control (QC) is the testing of materials, in-process samples and finished products.
- GMP covers people, premises, equipment, materials, production, documentation, quality control, complaints and recalls, and self-inspection.
- If it is not written down, it did not happen. Documents include SOPs and batch records.
- Each batch has a unique batch number so that it can be traced and recalled.
- Products are released only after the quality control unit approves them.
Quality in medicines
A medicine must have the right drug, in the right amount, free from harmful contamination, in a stable form that works as it should. Patients cannot judge this by looking, so quality must be built in at every step, not just tested at the end.
Key terms
| Term | Meaning |
|---|---|
| Quality assurance (QA) | The whole system of arrangements to make sure medicines are of the quality needed for their use. It includes GMP, QC and more |
| Good Manufacturing Practice (GMP) | The part of QA that ensures products are consistently produced and controlled to the required standards |
| Quality control (QC) | Sampling, testing and checking of materials and products, with documents and release procedures |
| Standard Operating Procedure (SOP) | A written, approved set of steps for doing a task the same way each time |
| Batch | A quantity of product made in one process, so that it is uniform |
| Batch record | The full record of how a batch was made and tested |
QA is the umbrella. GMP and QC are parts of it.
The main areas of GMP
| Area | What it means |
|---|---|
| Personnel | Enough trained, healthy, clean staff. Clear duties. Protective clothing and hygiene. Training records |
| Premises | Designed, built and kept clean to prevent mix-ups and contamination, with separate areas for stores, production, testing and packing |
| Equipment | Suitable, cleaned, calibrated, maintained and recorded |
| Materials | Bought from approved suppliers, tested, labelled, stored properly, and used by FEFO. Quarantine for materials not yet approved |
| Production | Done to written instructions, with checks at key steps, and measures to avoid mix-ups |
| Documentation | SOPs, specifications, batch records and logs |
| Quality control | Testing, release and retained samples |
| Complaints and recalls | A system to receive complaints and withdraw a faulty batch quickly |
| Self-inspection | Regular internal audits to find and correct problems |
Preventing contamination and mix-ups
- Separate areas and clear flow of people and materials.
- Line clearance: before a new batch, remove all materials, labels and documents of the previous product.
- Cleaning of equipment with records, and status labels such as "clean" or "in use".
- Labels for every container.
- Protective clothing, hand washing and no eating, drinking or smoking in production areas.
- Pest control and waste control.
- Quarantine of materials until they are approved.
Documentation
"If it is not written down, it did not happen."
| Document | Purpose |
|---|---|
| SOPs | Do each task correctly and the same way each time |
| Master formula and processing instructions | The approved recipe and method |
| Batch record | Shows that each step was done: materials used, weights, who did it, who checked, and results |
| Specifications | The limits that materials and products must meet |
| Logs | Cleaning, equipment use, temperature and training |
Rules for records: write at the time, in ink, sign and date, never erase, and correct by a single line with initials and a reason.
Quality control
QC covers:
- Raw materials: identity and quality, checked before use.
- In-process control: checks during production, such as weight, pH, fill volume and appearance.
- Finished products: tests for strength, purity, appearance, dissolution or disintegration, and microbial quality, as needed.
- Packaging materials and labels: checked for correctness.
- Retained samples kept for use if a problem appears later.
- Stability testing to confirm the shelf life.
A batch is released for sale only when QC confirms that it meets the specifications, and the batch record has been reviewed.
Worked examples
Yield. A batch should give 100 kg. 96 kg is obtained.
- Yield = 96 ÷ 100 × 100 = 96%
Each product has limits for acceptable yield. A yield that is too low or too high is investigated, as it may mean loss, error or a mix-up.
Label claim. A tablet is labelled 500 mg. A test finds 485 mg.
- Percentage of label claim = 485 ÷ 500 × 100 = 97%
Pharmacopoeias set limits, for example a range around 100%.
Complaints and recalls
- Every complaint about quality is recorded and investigated.
- If a product is faulty, the batch is recalled: stopped from sale and withdrawn from wholesalers, pharmacies and patients.
- Batch numbers and distribution records make a quick recall possible.
- The cause is found, and corrective action is taken to stop it happening again.
Self-inspection and regulation
Companies carry out self-inspections and external audits. In Nigeria, NAFDAC inspects manufacturing sites and requires GMP as part of registration and licensing. A technician working in manufacturing or in a hospital pharmacy that makes products should know and follow the site's GMP and SOPs.
Exam focus
- Define QA, QC and GMP, and state how they differ.
- List five areas of GMP.
- State why batch records are kept.
- Common mistake: using QA and QC as if they meant the same.
Quick check
Test yourself before you move on. Pick an answer to see the explanation.
1.Quality control (QC) is mainly concerned with:
2.Good Manufacturing Practice (GMP) is:
3.Why is a batch number given to every batch?
4.A batch should give 100 kg and 96 kg is obtained. What is the yield?
5.A tablet is labelled 500 mg. A test finds 485 mg. What percentage of the label claim is this?