In one of the important studies for Indian pharmaceutical industry, a group of scientists at National Institute for Pharmaceutical Education and Research (NIPER) established that the accurate long term stability test condition for pharmaceuticals for India is 30°C/70%RH, especially considering the southern most state, Kerala.

The new study, conducted under Dr Saranjit Singh, professor and head, Department of Pharmaceutical Analysis, NIPER, has its significance in view of the on-going process of finalisation of draft stability guideline by the World Health Oraganisation (WHO). The WHO draft is expected to come out with a list of long term stability test conditions for each of the 193 member countries.

At present, two storage conditions - 30°C/65%RH and 30°C/75%RH - are being considered as stability test condition for Climatic Zone (CZ) IV, which is similar to the climatic conditions in India. However, the long-term stability storage condition for India is not yet listed in the new draft WHO guideline that is under circulation for comments.

"The study observed that while rest of the country was covered well by stability storage condition of 30°C/65%RH, there were more humid tropical wet conditions in Kerala, where calculations indicated 30°C/70%RH as the right storage condition. Because the state of Kerala has the most population among the southern states, it could not be ignored for calculating storage condition for whole of the country. So the rightful condition for India can be considered as 30°C/70%RH," Dr Singh informed Pharmabiz.

He further added that WHO considers extreme condition in any part of a nation towards assignment of the storage condition for the whole country. The environmental conditions in Kerala are different from those in Brazil or The Association of Southeast Asian Nations (ASEAN), where 30°C/75%RH has been pushed as a requirement. Both Brazil and ASEAN have full humid environment throughout the year, while it is only monsoonal in Kerala.

He also pointed out that there are more than 25 countries in the world, which can be assigned 30°C/70%RH. Hence, there is a valid and scientific basis behind shifting to this stability test condition, which originally existed in WHO guideline of 1996, but was changed later.

The new data was presented by Dr Singh at The American Association of Pharmaceutical Scientists (AAPS) Workshop on 'Pharmaceutical Stability Testing to Support Global Markets' held at Bethesda USA in September 2007.

According to Dr Singh, the long-term stability test storage condition for India was calculated by taking ERA-40 reanalysis data compiled by European Centre for Medium-Range Weather Forecasts (ECMWF). The ECMWF data are global weather observations, collected at a resolution of 125 km covering the earth, and measurements are taken every 6 hours. The reanalyzed temperature and dew points from 1979-2002, averaged to monthly means, were used to determine vapour pressure and relative humidity in 18 cities across India. The same data and calculation procedure, which is being employed for the determination of long-term storage conditions for various countries in the new WHO guideline, were extended to India.