Biologics MKT Calculator (2–8 °C)

Most biologics (monoclonal antibodies, many protein therapeutics) are labelled 2–8 °C; some allow defined short-term room-temperature in-use periods stated on the label. The authoritative limit is whatever your product's labelled storage condition and stability data specify — read it off the marketing authorisation, the manufacturer's storage statement or the governing pharmacopoeia, and enter your real temperature history against it.

Biologics are generally less forgiving and more individual: proteins can aggregate when warm and denature when frozen, and many products specify a strict cumulative out-of-refrigeration time budget (e.g. a total number of hours at room temperature across the supply chain). MKT helps you assess the heat-driven stress of refrigerated excursions, but you must also track the freeze risk and the cumulative room-temperature time against the product's labelled allowance. Always work from the specific product's stability data — generic CRT-style excursion rules do not transfer to biologics.

Because degradation is not linear with temperature — it accelerates roughly exponentially (Arrhenius). A simple average treats an hour at 30 °C the same as an hour at 20 °C either side of 25 °C, but the product is harmed far more by the hot hour. MKT weights each reading by exp(−ΔH/RT), so it reflects the true cumulative chemical stress. It is always ≥ the arithmetic mean, and it is the figure regulators expect for storage and distribution compliance.

Use a representative series with durations — typically the logger's interval readings, or summarised blocks of 'X hours at Y °C' if you only have an excursion summary. The more granular the data, the more accurate the MKT, but the result is dominated by the warm excursions, so capturing those accurately matters most. Don't average data before entering it — that defeats the point; enter the temperatures and let the calculator do the kinetic weighting.