Film coating on tablets is a minor aspect of the tablet manufacturing process. However, if you are in the pharmaceutical industry, you are aware that the film coating material plays a crucial role in formulation design. 

These coatings had a humble beginning in protecting the tablets from the environment. However, with technological advances, now it does much more than that. 

In this blog, we will provide an overview of everything you need to know about these coatings.

What is Film Coating on Tablets?

Film coating is one of the commonly used tablet coating. Thin film coating are uniform layers applied to tablets or capsules. 

They’re made from a mix of:

• Polymers – for film formation (like HPMC, PVA)
• Plasticisers – to make the film flexible (like PEG, triethyl citrate)
• Colourants/Opaquants – for branding or light protection
• Solvents – water or organic, used to dissolve the mix

Once applied and dried, the coating forms a thin, protective, functional layer.

Why is Film Coating used?

Film coating materials are used to enhance the performance, appearance, and durability of tablets. They are commonly used to: 

• Protect the Tablet: Shields the core from moisture, light, oxygen, and heat and prevents degradation of sensitive APIs
• Improve Swallowability: Creates a smooth finish, making tablets easier to swallow.
• Mask Taste or Odour: Hides bitter, metallic, or unpleasant flavour. 
• Modify Drug Release: Supports sustained or controlled release over time.
• Enhance Appearance and Branding: Adds colour and gloss for better patient acceptance and supports brand recall. 
• Improve Mechanical Strength: Reduces dusting, chipping, or abrasion during handling, maintains tablet integrity and prevents tablets from sticking in packing.

Types of Thin Film Coating:

There are five main types of tablet film coating:

• Immediate-Release Film Coating: To improve the appearance and taste/odour of the tablet.
• Enteric Coating: To prevent its release in the stomach and reduce stomach irritation. 
• Controlled Release Coating: To maintain the rate of drug release. 
• Moisture-Protective Coating: To create a barrier against moisture and humidity.
• Functional Coating: For brand identity or to differentiate strengths.

Tablet Coating Process:

To apply a uniform film coating excipients to a tablet, the core of the tablet is first prepared by drying. A coating dispersion or solution is formulated with specific ingredients, such as pigments, polymers, colourants, and plasticisers. It is then sprayed on the tablets. Simultaneously, warm air is blown in to dry the coat. The coated tablets are then dried to remove moisture. 

Regulatory and Compliance Notes:

Thin film pharma coating must meet not just performance goals but also compliance standards, such as:

• GRAS status
• Compatibility with FDA, EMA or other regulatory bodies
• Label compliance according to market (Halal, Kosher, Vegan, Vegetarian, Allergen-free)

It is always recommended to check these early with your coating manufacturer to avoid derailing project timelines.

Coating Selection Checklist:

As a legacy tablet coating manufacturer, we’ve worked with countless formulations and production setups. We have created a list of questions that you should ask a coating manufacturer before finalising the film coating material.

• What’s the release profile required?
• Are there API stability issues?
• Is the coating compatible with API? 
• What regulatory markets are you targeting?
• Do you need moisture and UV protection?
• Is the coating process compatible with your equipment?

Tip: Run pilot batches before full-scale production. 

Advances in Film Coating Materials:

Film coating materials have undergone significant advancements over the years. One of the major shifts is towards the use of ready-mix film coating for tablets. This ready coating contains a blend of film coating excipients required. This tablet has significantly reduced operational errors and improved batch consistency.

Conclusion: 

Thin film coating excipients aren’t just ingredients. The right choice supports every function: better formulations, fewer batch failures, faster approvals, and smoother launches.
Novo is a leading manufacturer of tablet coating materials based in India. We specialise in manufacturing high-performance tablet film coating, including ready-mix formulations. Whether you’re developing a new product or troubleshooting an existing coating process, our team offers expert guidance tailored to your needs. Need help with your coating? Get in touch with us today for a consultation.

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