Mean Kinetic Temperature (MKT) is a simplified way of expressing the overall effect of temperature fluctuations during storage or shipment of perishable goods. MKT helps identify the ideal constant temperature during the cold chain process such as:
How is Mean Kinetic Temperature Calculated?
Technically speaking, MKT is an expression of cumulative thermal stress experienced by a product at varying temperatures during storage and distribution. In other words, MKT is a calculated, single temperature that is analogous to the effects of temperature variations over a period of time.
MKT is not a simple weighted average. The calculation of MKT gives the higher temperatures a greater weight when computing the average than would a simple numerical average or an arithmetic mean. This weighting is determined by a geometric transformation— the natural logarithm of the absolute temperature.
The International Conference on Harmonization (ICH) stability testing guidelines define MKT as ‘a single derived temperature which, if maintained over a defined period, would afford the same thermal challenge to a pharmaceutical product as would have been experienced over a range of both higher and lower temperatures for an equivalent defined period’. By using this unequal weighting pf the higher temperatures in a temperature series, MKT takes into consideration the accelerated rate of thermal degradation of materials at these higher temperatures. Therefore, MKT provides for the non-linear effect of temperature.
Where: ΔH = activation energy (typically from 60 to 100 kJ/mol for solids and liquids)
R = 8.314472 J/mol-K (universal gas constant)
T = temperature in degrees K
n = the number of sample periods over which data is collected
Note: ln is the natural log and ex is the natural log base.