Read the new Biogrund article on Hot Melt Coating:

Developments in the pharmaceutical industry require constant further development of technology in order to make products more effective, more stable, and safer. Hot melt coating (HMC) is an important application in the field of coatings. BIOGRUND, known for its expertise in developing customized solutions for the pharmaceutical, nutraceutical and cosmetic industries, is spotlighting this technology as part of its innovative coating solutions.

What is Hot Melt Coating?

Hot Melt Coating is a process where a solid, waxy substance is heated until it becomes liquid and then applied to a substrate. Once applied, the coating cools and solidifies to form a stable, uniform layer. Unlike traditional liquid coatings, HMC does not require solvents, making the process more eco-friendly and safer.

Hot melt coating (HMC) offers many advantages compared to conventional solvent-based coating technologies. It makes potentially toxic and expensive organic solvents such as ethanol and isopropanol superfluous.

The faster process results in higher batch throughput, leads to higher production volumes and increases productivity. HMC is also an effective method to mask the often bitter or sour taste of active ingredients and produce products with a pleasant mouth feel.

The functionality of Hot Melt Coating

HMC is a process in which coating materials such as lipids, e.g. carnauba wax and beeswax, are melted and applied to the active (on pellets e.g.) by a coating machine.

Step-by-Step Guide

• Spraying: The already melted coating components are sprayed onto the active ingredient through a heated nozzle. The active ingredient floats in a fluidized bed in the coating apparatus (e.g. Ventilus®/Romaco Innojet).
• Wetting: The active ingredient is wetted with the coating components.
• Solidification: As the coating has a lower melting temperature than the active ingredients, it cools on the surface of the active ingredients.
• Homogeneous coating: A homogeneous layer consisting of 100% coating material is formed.

Process times can be significantly shortened

A comparison of the HMC with a polymer coating can confirm this. The HMC process takes 42 minutes and is therefore almost seven times faster than the process with the polymer solution, which takes 278 minutes. In both processes the weight of the granulate is 1000 g, the spray rate is 12 g/min and the use of wax or polymer, 500 g.

Because the wax is a melt, there is no suspension (= 100% solid content). The polymer, on the other hand, must be dissolved in water or in an organic solvent. In this example the amount of water is 2833 g. This means that more product is needed to coat the granulate.

Advantages and disadvantages of HMC

BonuWax® – a ready-to-use HMC premix

The excipient premix is a water and solvent free application and provides good moisture sealing, taste masking and stability for granules, particles and pellets.

BonuWax® is formulated with different natural waxes and is highly stable to provide excellent transparency, anti-sticking properties (effective separation) and enhanced mechanical stability/flowability during processing and packaging.

It can also be used to wax tablets, soft capsules or sugar-coated tablets to achieve a glossy surface, non-stick properties and better swallowability of the dosage form.

Read more Biogrund studies here:

Case Study: Biogrund Whitepaper_BonuWax:

Brochure: Biogrund BonuWax:

YouTube: Hot Melt Coating | HOW TO coat pellets with a Hot Melt Coating product | BonuWax® – BIOGRUND

Source: Biogrund, website Hot-melt coating

Read also the following articles on Biogrund Hot Melt Coating (HMC):

• Advantages and disadvantages of Hot Melt Coating
• The functionality of Hot Melt Coating
• Why Hot Melt Coating?

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