Tablets: ice cold, bone dry and lightning fast

This is not only practical but also makes it easier for people who have problems swallowing to take medication. The tablet can dissolve so quickly because of how it is produced: it is freezedried and has a very porous structure. Water in the saliva can therefore penetrate immediately, dissolve the tablet and release its active ingredients. In the Innosuisse-sponsored project, the HLS researchers developed a system where tablets are formed directly in the final packaging. Rohrer built a laboratory-scale prototype machine which fills the blister pack cavities, first with a solid mixture and then with a liquid containing active ingredients and auxiliary substances. The damp mass is frozen with liquid nitrogen before a vacuum pump extracts the water from the tablet. It is vital that the ice does not melt but goes straight to a vapour; if not the tablets clump and cannot dissolve as quickly. The researchers systematically refined the mix ratio, temperature and vacuum strength so that the tablets can be removed from the pack undamaged and will dissolve in the mouth within ten seconds, with no unpleasant sensation. Compared to conventional freeze-drying, which often takes a day or more, the HLS team have reduced the drying process to a few hours. They have already tested the patented process for active ingredients such as insulin, ibuprofen and vitamin C.