Why Hot Melt Coating?

Hotmelt coating with BonuWax; copyright: Biogrund — Hotmelt coating with BonuWax

Disadvantages of solvent-based coatings and why alternatives are needed

The coating of active substances requires the suspension of the auxiliary substances in a solvent. This mixture is then applied to the active ingredient particles. If water is involved, drying is required. This process is time-consuming and costly, as heat energy is required. Other solvents that are considered are alcohols, ethers and ketones. Because they are highly volatile, they dry quickly. On the other hand, it is technically complex, as they have to be removed from the active ingredients.

Active ingredient coating by means of Hot Melt Coating

In the pharmaceutical and food supplement industry, the problem often arises that with solid oral dosage forms, the active ingredient remains in the mouth longer and the taste is perceived more intensively than desired. This can usually be unpleasant for the user and in some cases it can also cause a gag reflex.
A further challenge is the targeted release of the active ingredient, as well as ensuring the protection and stability of the solid oral dosage form and, if necessary, increasing the active ingredient content. In order to meet these requirements, various coating processes have been used to date, which among other things could not guarantee increased stability of tablet blanks or were time-consuming.

A good process, the so-called Hot Melt Coating (HMC), is to be used for encapsulating active ingredient particles. It is intended to save costs and time, make handling easier, replace solvent-based encapsulation processes, guarantee increased stability and improve user-friendliness.