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   5. Secondary manufacture
Case study: manufacturing tablets (continued)
In the first three pages of this chapter we have seen how the ingredients are received, checked, granulated, dried and shaped into a tablet. The last stage is the coating.
Photo of coating machine
Picture 5.8 A coating machine.
6. Coating
Some tablets are then coated. The coating performs a number of jobs. For example it can be to:
  • prevent the tablets cracking or breaking in transit
  • allow the controlled release of the active ingredient over a longer time than simply allowing the tablet to dissolve
  • mask the taste
  • prevent the tablet from breaking up
  • make the tablet easier to swallow.
The coating machine is like a tumble drier with nozzles suspended across the width of the drum. The batch of tablets is rotated in the drum and the nozzles spray on the coating. Baffles attached to the inside of the drum ensure that every tablet is coated properly.

Once again, the coating process is very carefully controlled. This is to ensure that the coating on every tablet is even and is the correct thickness. There could be half a million tablets in the coating machine. So an error could be extremely expensive.

The production of the tablet is now complete. It is ready to be tested and then packaged before leaving the factory.
Question 4

Look at the statements about coating below. In each case, decide whether it is true or false. Make your choice using the drop down menu.

Coating . . . . T/F
a) . . .  makes the tablets easier to swallow.
b) . . .  is part of primary manufacture.
c) . . .  ensures the medicine is evenly distributed within a tablet.
d) . . .  masks any unpleasant taste.
e) . . .  protects the tablet against breakage.