Merck/Sensitech study highlights methods to analyze CRT parcel shipping

Evolving US and EU regulations for shipping pharma products now include controlled room temperature (CRT) products—those whose label specify storage between (generally) 15-30°C; and these constitute more than 90% of all pharma products. (The exceptions are those that require cold-chain—2-8°C—or frozen storage.) Many CRT products are shipped in bulk under controlled conditions, but down the supply chain, shipments start being broken into individual cartons, and many of these ship as general small-parcel freight. Thus, the question becomes, how to ensure that small-parcel shipments are sufficiently protected to ensure their quality when they reach the point of dispensing?

A study presented by Michael English, associate director of engineering at Merck, and David Magargee, a senior project manager at Sensitech (Beverly, MA), provides some answers—and a methodology to address regulatory concerns. Merck did temperature profiles of two years’ worth of domestic (US and Puerto Rico) shipments of small parcels to customers, recording temperature profiles of each of the more than 9,000 trips. To crunch the data, Sensitech has developed (and applied a patent for) a method to calculate “heat exposure” (the duration and extent of temperature excursions outside the label specification of the product). To be precise, excursions themselves do not adulterate a product; stability testing is performed during a product’s approval process to determine how much temperature, and how long an exposure duration, affects the product quality.

The end results: developing a shipping-lane profile in this manner may provide a cost-saving rationale for a thermal protection system (that is, the profile might show how little protection is actually necessary). The authors also recommend developing a “stability budget”—an evolving approach to measuring the resistance of a pharma product to heat-related damage. Another factor to consider is widening the CRT range (one common example is 5-30°C) that matches the ambient environment products will experience. One caution, as well: the study found that there can be significant instances of shipments occurring outside the “normal” profile of winter or summer temperature profiles; dividing a year’s shipments into these two ranges has been a conventional way to approach regulatory compliance.

The study was presented at the PDA/FDA Supply Chain meeting (June 3-5, Washington, DC).