I have a question regarding coating of tablets. For practice I have some tablets comprised of Microcrystalline Cellulose (MCC) and Lactose.
I have made different solutions of Povidone, Ethanol 96 %, Shellack and the color additive. I am using a standard sugar coating Pan, with the ability to apply heated air from a fan.
I apply the coating solution with a handspray, since no spray is available on the Pan system. Everytime I apply the solution it dissolves my tablets. I have tried to apply it more slow and I have used IPA as solvent, since MCC and Lactose should have less solubility in this alcohol, but still it dissolves my tablet. If I turn up the heating fan to 80 or 100 degrees, and spray it onto the tablets, they are coated, since the solvent evaporates instantly, but it leaves marks from the color additive and they are not coated "all over" as they would if they had time to share and roll around with the coating material on.
I have also tried to precoat with a polymer, but it does not seem to help. Are there anyone having great experience with coating tablets which could help with this issue? I would prefer to be using fludisation equipment to coat them, since this seems more easy for a film coating, compared to be using a sugar coating drum pan. But I dont have that available.
Any replies would help.
Thanks in advance and merry christmas to your all