Three months of accelerated data and a requested 24-month shelf life

India is a Zone IVb market. The long-term condition is 30 ± 2 °C/75 ± 5% RH and the accelerated condition is 40 ± 2 °C/75 ± 5% RH for six months, on at least three primary batches (two at least pilot scale, same process and same container-closure).

Significant change. The standard criteria for a drug product are: a 5% change in assay from the initial value; any specified degradant exceeding its limit; failure to meet appearance, physical, dissolution, pH or preservative specifications. Apply them batch by batch:

• The assay fall is 4.8 percentage points: just inside the 5% trigger, so not decisive.
• Total impurities at 1.9% against a 2.0% limit is not itself a breach, but the individual degradant (pantoprazole sulfone) must be checked against its own limit.
• The acid-resistance failure in one batch is a failure to meet specification, and therefore a significant change. One failing batch out of three is sufficient; results cannot be averaged across batches.

Consequence for the shelf life. Where a significant change occurs at the accelerated condition, ICH Q1E permits no extrapolation beyond the period covered by long-term data. Here the long-term data are effectively zero, so no extension beyond the existing 12 months can be granted. Extrapolation of even 3 months requires six months of accelerated data with no significant change.

Also note the trend, not just the point estimate: a 1.5 percentage point impurity rise in three months predicts failure before 24 months.

Study package to be required.

1. Six months of accelerated data at 40 ± 2 °C/75 ± 5% RH on three primary batches, with no significant change in any batch, plus long-term data at 30 ± 2 °C/75 ± 5% RH to at least 12 months, with a commitment to continue to 24 months.
2. Supporting data at the intermediate condition if any accelerated result is borderline.
3. Batch data from production-scale, not laboratory, coating equipment, showing enteric polymer weight gain, curing time and temperature, and acid-resistance results at release and on stability.
4. Data on the individual degradants, not only total impurities, and on dissolution profile change (multi-point, not single-point) during storage.

Packaging. Pantoprazole is acid-labile and moisture-sensitive, and the failure mode here is moisture ingress through a PVC blister causing coat rupture and sulfone formation. PVC is a poor moisture barrier. The applicant should switch to a aluminium-aluminium (cold-form) blister or an appropriate high-barrier laminate, and repeat the stability study in the proposed pack, because stability data are only valid for the container-closure actually studied.

Interim position. Retain the approved 12-month shelf life. If the company wants a shorter intermediate extension once 6-month long-term data are available, that can be assessed on its merits, but the burden is on the applicant and the default is refusal.

Ancillary requirement. A post-approval stability protocol with at least one batch per year on the market, and a commitment to report out-of-specification trends to the licensing authority.

Refuse, and record the refusal.

The legal position. The shelf life of a drug is part of the approved particulars of the licence and of the label. The expiry date must be supported by approved stability data and must not exceed the shelf life approved for that product and pack; the manufacturer cannot unilaterally extend it. Printing a 24-month expiry on a batch that is only supported to 12 months makes the label carry a false particular and exposes the batch to action as misbranded, quite apart from any quality failure.

Immediate steps.

• Direct the firm in writing not to use any cartons, foils or labels already printed with the 24-month expiry; require destruction or supervised overprinting under records.
• Require the current batch to be released, if at all, only with the approved 12-month expiry and the approved pack.
• Inspect the printing and packaging stores to confirm the quantity of non-compliant printed material and to establish whether any batch has already been dispatched with the longer date.
• If any batch has gone out with the unapproved expiry, treat it as a recall matter and require a market withdrawal with documentation.

Wider signals. A firm that tests into compliance on one point is likely to do so elsewhere. Review its recent batch records, out-of-specification investigations and previous stability commitments, and consider whether the responsible person has signed declarations that are demonstrably untrue.

Communication to the applicant. State plainly what data will support a 24-month claim, so that the refusal is reasoned and appealable rather than a bare denial.