SOP for Sampling of Packing Material: Example with AQL Tables

In short: This is an example SOP for sampling printed and plain packing material (foils, films, bottles, cartons, leaflets, labels, shippers) when it arrives at a pharmaceutical plant. It covers quarantine checks, how many packs and units to sample, visual inspection against an acceptance quality level (AQL), and the records to keep. All sample sizes and defect limits shown are example in-house criteria; adapt them under your own quality system and approved suppliers’ specifications.

Why sampling of packing material matters

Packing material protects the product and carries the legal information a patient relies on. A mixed-up label or leaflet can be as dangerous as a wrong tablet. Sampling takes only a small part of a consignment, so the sample must be representative and handled so that materials cannot be mixed up. EU GMP Annex 8 makes the point that valid conclusions cannot rest on non-representative samples, and that samplers need training in the sampling plan, written procedures and techniques. WHO’s sampling guidelines (TRS 929, Annex 4) add that printed packaging is easy to mix up during sampling, so only one material should be handled at a time, and that a consignment may not be uniform (different production days, machines, printing stations or source materials), so sampling should be random and may also be focused on such points. They also say that plans for packaging materials should be based on a defined sampling standard such as ISO 2859, ANSI/ASQ Z1.4 or BS 6001-1. Annex 8 (paragraph 5) adds that the plan should take into account the quantity received, the quality required, the nature of the material (primary or printed), the production methods and what audits show about the supplier’s quality system, and that the number of samples should be set statistically.

Printed packaging also needs secure storage with access limited to authorised people, and issue only under an approved, documented procedure (EU GMP Chapter 5, section 5.46).

Example SOP

This is an illustrative template. Numbers, forms and responsibilities must be set by your own quality unit.

1. Objective

To define how packing materials are sampled, inspected and accepted using a sampling plan and an acceptance quality level (AQL).

2. Scope

Applies to the sampling and AQL-based acceptance of all primary, secondary and tertiary packing material received at the Quality Control department of a pharmaceutical manufacturing plant.

3. Definitions

• Primary packing material: in direct contact with the product, for example foil, PVC, PVDC, bottles.
• Secondary packing material: holds the primary pack, for example printed cartons and package inserts.
• Tertiary packing material: holds secondary packs for storage or transport, for example corrugated shippers.
• AQL (acceptance quality level): the highest percentage of defective units still accepted as satisfactory, used to set acceptance and rejection numbers in the sampling plan.
• GIM: goods inward memo. A.R. No.: analytical reference number.

4. Responsibilities

• Stores: keep received material in quarantine, with labels, and issue the GIM.
• QC officer / sampler: sample, inspect and record as per this SOP.
• QC head or designee: review results and approve or reject.
• QA: oversee compliance with this SOP.

5. Procedure

5.1 Before sampling

1. The QC section head or designee enters the consignment in the packing material inward register (Annexure 1) on receipt of the GIM.
2. Confirm that stores have affixed “Quarantine” labels on all containers, boxes or rolls (for corrugated boxes, per bundle), and check the material against the GIM: quantity, number of rolls or packs, and condition of the consignment.
3. Check the identity details: material name, manufacturer, quantity received, total number of rolls or packs, and that the supplier’s status label is on each pack.

5.2 Sampling rules

1. Wear gloves and masks where required.
2. Sample by A.R. No. Never sample two A.R. numbers at the same time, and handle one material at a time to prevent mix-ups.
3. For cartons printed in multiple-up sheets, check every up of the sheet.
4. Draw samples randomly from different packs, using the plan below.
5. After sampling, stamp “SAMPLED” in black ink across the quarantine label so that the stamp falls partly on the label and partly on the pack, with signature and date. Do not stamp packs from which no sample was taken or whose sample will return to the store.
6. Reseal the pack with QC-sampled tape and affix the sample label (Annexure 4).

5.3 Visual inspection and spot checks

Check the consignment for defects such as: wrong or misaligned printing, improper pasting, loose or telescopic winding, wet or damaged packs, unusual odour, cuts, dents, damaged core or edges, wrinkles in foil, PVC or PVC/PVDC film, sticking of cartons, and oil, grease, dirt, dust, fibres, stones or insects.

For reel material, remove at least 3 m of printed aluminium foil, plain aluminium foil, PVC and PVC-coated PVDC film for visual inspection, and cut a further sample for laboratory analysis (example criterion: 3 m printed foil, 2 m for the others). For cartons, inserts, shippers, labels, bottles, tapes, poly bags and applicators, draw samples for visual inspection and analysis from the tables below. Record everything on the visual inspection checklist and sampling report (Annexure 2).

5.4 Sampling plan (example in-house criteria)

Table 1. Number of packs to sample from the packs received

Table 1A. Number of units for visual inspection and for complete analysis

Table 1B. Acceptance numbers for visual inspection, normal inspection (Ac = accept at or below; Re = reject at or above). Critical defects (AQL 0%): Ac 0, Re 1 at every lot size.

Defect classes (example)

• Critical (AQL 0%): a defect that could make the finished product unsafe, a potential risk to the patient.
• Major (AQL 1.0%): a defect, other than critical, likely to cause failure of the product or process during manufacture, testing, shipment, storage or use, but not a direct patient risk.
• Minor (AQL 2.5%): a defect that affects appearance but is expected to have little or no effect on suitability for use.

Example defect list by material

Add a functionality test as per the respective specification where required.

5.5 Drawing and returning samples

1. Select boxes at random and draw about equal quantities from each.
2. Check the units against the AQL. Put non-defective inspected units back into the same boxes so the box quantity stays as before; keep any leftover in the last sampled box.
3. Worked example: 25 packs of printed cartons arrive, 10,000 cartons in total. Table 1 gives 5 packs to sample; Table 1A gives 200 cartons for visual inspection and 15 for analysis. Take 40 cartons from each of the 5 packs, check every up of the multiple-up sheet and do the spot check, then set aside 15 for QC analysis.
4. For complete testing, draw the number in Table 1A; for BOPP tape and poly bags, test 3 units. Silica gel and BOPP tape samples go back to the packing material store after analysis.
5. For corrugated boxes, do visual inspection as per AQL and check dimensions on 3 boxes during sampling, recording them in Annexure 2.

5.6 Deducting sample quantity in ERP/SAP (example)

Some materials are sampled in metres or numbers but stock is kept in kilograms, so deduct the approximate weight:

5.7 Acceptance and rejection

All results must comply with the respective specification. If the sample does not meet the AQL, reject the material.

6. Records and retention

Keep the inward register, visual inspection checklist, sampling report and analytical records as GMP records for at least 1 year after the expiry date of the respective product batch in which the material is used, and longer if local law or the marketing authorisation requires (EU GMP Part I, Chapter 4, section 4.11; 21 CFR 211.180(a)).

7. Annexures

Annexure 1: Packing material inward register columns: serial no., GIM date, GIM receipt date, item name, item code, GIM no., A.R. no., receipt quantity, manufactured or supplied by, sampled by and date, analysed by and date, released status (approved or rejected by and date), remarks.

Annexure 2: Visual inspection checklist and sampling report: item name and code; GIM no.; A.R. no.; manufacturer or supplier; date of receipt; quantity received; packs received and sampled; quantity for visual inspection and for analysis; spot analysis (physical appearance of the consignment, visual inspection per AQL, storage condition: complies, does not comply or not applicable); dimensions where relevant; remarks.

Annexure 3: “SAMPLED” stamp (design per site).

Annexure 4: Sample label: Quality Control Department, sampling of packing material; item name; batch no.; A.R. no.; sampled quantity; roll or pack no.; manufacturer or supplier; signature and date.

Related reading

• SOP on sampling of raw materials
• Good documentation practice: specifications, packaging materials and retention of documents
• SOP for vendor management

Frequently asked questions

Is the sample size in this SOP a regulatory requirement?

No. Regulators ask for a sound, documented sampling plan based on a recognised standard. The tables here are an example plan; your own plan must be justified and approved.

Why can sampling two A.R. numbers together cause problems?

Printed items from different lots look alike. Sampling one lot and one material at a time is the simplest control against mix-ups.

Can I reduce testing of packing material from approved suppliers?

EU GMP Chapter 5 (paragraphs 5.35 and 5.36) allows partial or full use of a supplier’s test results only for starting materials, under conditions that include audits, and still requires identity testing of each batch. It gives no such allowance for packaging materials; it asks that suppliers of primary and printed packaging be qualified with the same care as starting-material suppliers (paragraph 5.45), and Annex 8 lets audit knowledge of the supplier shape the sampling plan. Any reduced testing must be justified in your supplier qualification SOP, and the finished-product manufacturer remains responsible.

References

1. European Commission. EudraLex Volume 4, EU GMP Guide Part I, Chapter 5 (Production), in operation since 1 March 2015: paragraphs 5.35 and 5.36 (supplier test results for starting materials), 5.45 (packaging material suppliers) and 5.46 (printed packaging materials).
2. European Commission. EudraLex Volume 4, EU GMP Guide, Annex 8: Sampling of Starting and Packaging Materials (principle, paragraph 1 on training, paragraph 5 on packaging material).
3. WHO Technical Report Series No. 929, 2005, Annex 4: WHO guidelines for sampling of pharmaceutical products and related materials, sections 4.4 and 5.2.
4. EU GMP Part I, Chapter 4, section 4.11; 21 CFR 211.180(a).