Last-Mile Pharmacy Delivery MKT Calculator

Direct-to-patient and pharmacy last-mile deliveries of refrigerated medicines must keep the product within its 2–8 °C condition during the short but uncontrolled final leg. 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.

Include a small data logger or a qualified phase-change cool-box with a temperature indicator in the delivery, and on return compute the MKT over the delivery window against the product's 2–8 °C condition. Because last-mile legs are short, the calculation is dominated by any warm spike (doorstep wait, car interior), so capturing the actual delivery duration and conditions matters. Qualify your packaging for the worst-case delivery time and ambient, instruct couriers on not leaving medicines in hot vehicles, and keep the logger record as proof of cold-chain integrity for that patient's medicine.

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.