Impact of repackaging on the physical stability of tablets in hospital pharmacy practice

Background and Objectives
Hospital repackaging facilitates unit-dose dispensing but exposes tablets to storage conditions that differ from those of the original manufacturer’s packaging. In our hospital pharmacy, the internal beyond-use date (BUD) is set at 6 months and reduced to 3 months for medicines supplied with a desiccant in the original container. The aim of this study was to evaluate the impact of repackaging into unsealed amber PVC blister cavities without secondary packaging on the physical stability of tablets stored under routine hospital pharmacy conditions.

Methods
Five medicinal products were included: Biktarvy^®, Triumeq^®, Tivicay^®, Modopar^® and Sevelamer. For each product, two groups were established: a reference group, stored in the original container opened on Day 0, and a test group, repackaged according to routine hospital pharmacy practice. Twenty tablets per group were included.
Tablets were stored at ambient room temperature in the hospital pharmacy and evaluated on Day 0, Day 7, Day 14, Day 28 and Day 50. The following parameters were assessed: individual weight variation, friability, crushing strength (tablet hardness), and a standardized visual score including adhesion to the blister cavity, cracking, film-coating alteration, surface friability, and changes in colour or odour.
According to the European Pharmacopoeia, a friability value ≤1% was considered compliant. As no published acceptance criteria are available for weight variation following repackaging, internal thresholds were established: <1% was considered stable, whereas >2% was considered unstable.

Results
Distinct stability profiles were observed among the medicinal products.
Triumeq^®, Biktarvy^® and Sevelamer demonstrated good physical stability, with absolute weight variations below 1%, no notable visual alterations and no meaningful deterioration in mechanical properties.
Tivicay^® showed a mean weight increase exceeding 2%, without visual abnormalities or marked increases in friability, suggesting an intermediate profile suggestive of moisture uptake and requiring cautious interpretation.
Modopar^® exhibited the greatest degree of physical alteration, with increased tablet weight, marked visual deterioration, substantially higher friability and a pronounced decrease in tablet hardness.

Discussion and conclusion
The impact of repackaging depends on the medicinal product considered. Under the conditions evaluated, Triumeq^®, Biktarvy^® and Sevelamer appeared compatible with the repackaging procedure investigated, whereas Modopar^® demonstrated poor physical stability. Tivicay^® requires particular caution.
Published data on hospital tablet repackaging remain scarce, highlighting the need to generate local stability data to support evidence-based repackaging practices and appropriate beyond-use dating. These findings support an individualized approach to hospital repackaging based on the physicochemical characteristics of each medicinal product.