The 2010 Union Health Ministry statistics showed that nearly 128 children died even after immunization (Ram, 2011). Speculations have attributed the loss in potency of vaccines to a break in the cold chain. This is because most medicinal products are temperature sensitive and need to be maintained within a required temperature range. Exposure to temperature beyond this range leads to reduced efficacy of products. As of 2012, Indian pharmaceutical industry is valued at US $22 billion according to the Department of Pharmaceuticals of the Indian Ministry of Chemicals and Fertilizers (ibef, 2013). Indian pharmaceuticals industry is ranked third in the world. However, if the medicines have lost their potency, then despite being the third in the pharmaceuticals industry, it does not serve any purpose. Support from international bodies like Bill and Melinda Gates Foundation has put India in a progressive mode to develop an effective pharmaceutical supply chain. The objective of this article is to bring forward the evolution of medical transportation in India and the upcoming technologies that can make transportation both efficient and economical.
Passive and active technologies
There are two major methods for transportation of temperature sensitive products - active and passive systems of temperature control. Active systems include freezers, refrigerators or cold rooms with size scaling from single pallet size to a full vehicle..They can provide high levels of thermal protection to external temperatures. It can accurately maintain the desired temperature, be it -20°C or +40°C. Active systems need constant power supply in the form of fuel, battery or external power sources. Since we are always short on power supply, therefore, usage of active systems becomes difficult and expensive. This creates space for passive systems that once assembled,do not need a constant source of power supply.
Passive packaging solutions vary in size. Depending upon the size of system it can be designed as a single dose or multi pallet system. The system comprises the payload material surrounded by a thermal media, prepared to serve a particular temperature range. This system is packed inside an insulated container. This basic container allows for the system to be shipped without significant handling restrictions. Different thermal media is used for different temperature ranges, thus providing temperature protection within 2° C to 8°C, 15° C to 25°C, and -25°C to -15°C. WHO has delineated these three temperature ranges as refrigerated (2°C to 8°C), controlled room temperature (15°C to 25°C) and frozen (-25°C to -15°C).
Current scenario of medical transportation
Currently gel packs are used as the thermal media for the payload. These gel packs are essentially water converted into gel form using a thickening agent. Since these gel packs are essentially water, it provides a cheaper solution for transport of pharmaceuticals. These gel packs are frozen in a deep refrigerator and when it changes to solid phase (which is typically ice at 0°C), it is packed around the payload to provide a cooling effect.
For refrigerated products, these frozen ice packs are observed to be inefficient as they freeze at temperatures below 0°C. The refrigerated products have to be maintained within 2°C to 8°C. When the products come in contact with these frozen packs, it results in a thermal shock as they are at below 0°C. The products therefore lose their potency. However, due to lack of stringent government regulations, freight forwarders continue using gel packs as the thermal media due to its easy availability and giveaway price.
For frozen products, conventionally, dry ice is used to maintain sub-zero temperature. This leads to temperatures dipping to as low as -60°C to -80°C, which is again objectionable for the vaccines.
These cheap solutions turn out to be a losing strategy. Loss in product efficacy during transport pose a danger to the health of patients. GAVI Alliance, a public-private partnership of members, including WHO, UNICEF, World Bank, and the Bill and Melinda Gates Foundation has been supporting India for its immunisation programme since 2002. All this support goes in vain if proactive measures are not taken in the direction of safeguarding pharmaceutical products in the supply chain. WHO has updated its guidelines for transportation of vaccines and the responsibility is now on logistics provider and pharmaceuticals to guarantee the supply of vaccines. This calls for a shift from existing practice of using gel packs, ice packs and dry ice.
Phase change materials
With the advent of Phase Change Materials (PCM), these limitations can be easily concurred..Phase change materials are basically chemicals formed either using hydrated inorganic salts or organic mixtures. They make use of their latent heat capacity to absorb/release heat to keep the product at required temperature range. The major property of a PCM is that it can be created to serve specific temperature ranges with change in its chemical composition. For eg: For a payload to be maintained at 2-8°C, we would choose a PCM of 5°C. This means that it freezes at a temperature below 5°C and melts at a temperature above 5°C. During melting or freezing, it absorbs a large amount of heat in the form of latent heat to undergo a phase transition. That means that a large amount of heat is absorbed without change in temperature (that’s why it’s called latent heat) .This makes it a good substitute for ice packs.
The advantage of PCM is two fold: It can provide an efficient thermal protection to medicinal products within desired temperature range .This makes it possible to transport pharmaceuticals without losing its effect; and PCMs reduce the quantity of coolants used, as its latent heat is usually high. The volume of packaging reduces by almost a factor of 30 per cent, providing an economic incentive to the freight forwarders for using PCMs as the thermal media.
Supply chain of pharmaceuticals has evolved with new drug discoveries. There is still a reluctance in the mindset of people when it comes to adapting to new technologies,whether it is due to the initial cost of experimentation or the fear towards the new! Making patient health a central agenda, government institutions, freight forwarders and pharmaceutical companies should take collective measures to ensure proper utilisation of funds, in the field of medicine as well as in its transportation measures.
(Vishnu Sasidharanm is manager, Business Development &
Paramjot Singh is associate, Business Development, Phase Change Materials, Pluss Polymers Pvt. Ltd)