| Bradley Smith at Colt International Ltd outlines the reasons why maintaining product quality is of paramount importance to any organisation
For the pharmaceutical industry, like the food industry, it could be said that scrutiny over quality is that much greater – and understandably so. The mean kinetic temperature (MKT) requirement places a significant responsibility on all managers of pharmaceutical storage facilities. It is generally accepted as the yardstick by which quality storage is measured, and forms an integral part of the auditing procedures by the Medicines and Healthcare Regulatory Authority (MHRA).
The MKT is defined by the United States Pharmacopoeia (USP) as a:
“single calculated temperature at which the total amount of degradation over a particular period is equal to the sum of the individual degradations that would occur at various temperatures”.
It is a calculated, fixed temperature parameter, which simulates the effect of temperature variations over a period of time. In particular, it takes into account the likelihood of accelerated product degradation due to high storage temperatures. It is not a simple averaging calculation because it gives greater weighting to higher temperatures in determining the average from a datum. Whilst high ambient temperatures haven’t always been a feature of British summers, recent experience has highlighted the need to plan for preventive action. So what means are available to help control storage conditions to within the MKT? There are three approaches that can be considered: air conditioning; ventilation; and evaporative cooling.
AIR CONDITIONING
This is better described as comfort cooling (true air conditioning involves the regulation of humidity levels as well as temperature) and usually comprises indoor cooling units (evaporators) and external condensing units. By circulating a refrigerant gas (traditionally a hydro chlorofluorocarbon – HCFC) the system cools air to reduce temperature. The ubiquitous split-system units, found in many offices and shops, would be ineffective in all but the smallest storage facilities. In terms of cost, pharmaceutical warehouses are normally too large for refrigerant cooling systems. Large capacity commercial systems, as shown in Figure 1, can be applied, but the investment costs are significant, as are the operating costs. |
