The international acceptance of the definition of controlled room temperatu
re (CRT) has given additional impetus to the use of mean kinetic temperatur
e (MKT) as a method of quantifying temperatures during transport and storag
e and consequent possible effects on drug product stability. The present pa
per explores some of the implications of the MKT concept and considers the
effect of temperature excursions on MKT values and hence on stability of dr
ug products.