Enteric vs Film Coating – How Do They Compare?

At times, you may wish to add unique properties on capsules or pills after production process. In such circumstances, you can choose either enteric coating or film coating.

Well, the two are important postproduction processes in the pharmaceutical industry. But, at what time should you choose either enteric coating or film coating?

Let’s explore.

What is Film Coating?

You can add a thin, consistent layer of film coating to a pill or capsule. It enhances appearance, acts as cover up for taste or smell, shields it from moisture or light. Film coatings are the best for the drugs that do not need targeted delivery since they dissolve in the stomach.

They are easy to apply and quite common in pharmaceuticals production.

What is Enteric Coating?

This is the outer layer of a drug that is applied on it to protect the drug from acid in your stomach ensuring it travels to the gut without dissolving. This coating breaks down at higher pH levels yet is resistant to stomach juices.

For medications that are acid-sensitive or that can irritate the stomach lining, it is essential to provide targeted and delayed drug release. One of the most popular option is the acid resistant capsules.

Key Differences Between Enteric and Film Coating

· Solubility and Disintegration Environment

You should think about the way each coating acts in the body. Film coating readily dissolves in the acidic condition of the stomach, this allows its use in the drugs that are able to survive low pH levels. But stomach acid has little effect on enteric coating, which only dissolves at the intestine’s higher PH, which is frequently above 5.5.

This selective disintegration prevents early destruction of enteric coated drugs and immediate response of the film coated drugs after ingestion. Using an enteric acid is your go to when you need the drug to travel to the gut without being absorbed. Otherwise, general purpose delivery occurs at a faster rate through film coating.

· Purpose and Protection Level

When opting for enteric and film coating, consider the needs of the drug’s protection. Film coatings mainly enhance product appearance, conceal taste or odor and protection against light or moisture. They fail to protect drugs from the acid of the stomach.

Enteric sole work is to make sure that the drug you ingest is not attacked by acid. This makes the drug to remain stable until it enters the intestines. Use enteric coating for acid-sensitive drugs or drugs which may irritate the stomach. Film coating is adequate protection for the non-sensitive drugs with less manufacturing process involved and faster onset of action.

· Application Materials

You use various polymers and ingredients depending on the type of coating. When applied to films, the coatings utilize water-soluble materials such as hydroxypropyl methylcellulose (HPMC) and plasticizers that dissolve easily in the stomach acid. Enteric coatings need pH sensitive material for example; cellulose acetate phthalate (CAP) or Methacrylic acid copolymers, withstand acid but dissolve in a neutral to basic pH.

Choosing these materials has direct impact on performance, costs, and time to manufacture. Enteric-specific materials are only required in cases when the formulation requires targeted delivery as these gels require more complex preparations. And long curing times than the general film coatings.

· Release Timing and Absorption

Based on the coating type you affect how fast a drug works. Film coatings permit immediate or somewhat delayed release of drug in the stomach, resulting in faster absorption and onset. Enteric coatings only allow release upon entering the small intestine, perfect for time-critical or targeted therapies.

Such a difference has a direct impact on bioavailability, particularly, for those drugs that degrade in acid or need to get to particular absorption sites. However, if instantaneous effect is paramount, film coating is superior. When delayed release is required to either protect the medication or control timing, delivering the medication in a controlled manner for optimal absorption.

· Use in Drug Delivery

Drug delivery strategies are affected by your choice of coating. Film coatings are only appropriate for more broad-based applications such as over-the-counter painkillers or vitamins that do not need site specific release. Drug delivery methods that need to avoid the stomach, including probiotics, enzymes, or anti-inflammatory medications, require enteric coatings.

They help to prevent the acid degradation of active ingredients and direct action of the drug in the gastrointestinal tract. Knowing the role of coating, you guarantee therapeutic efficiency, reduce side effects and meet requirements for drug-release. Eventually, your decision should correlate with the chemical profile and target site of action of the drug.

Let’s have a summary in the table below:

Which One Should You Choose?

If your aim is to improve appearance, hide taste, or supply fundamental coverage for your drug, film coating should be your drug coating. It’s less time-consuming to apply, affordable, and suitable for drugs that aren’t destroyed by stomach acid. When you are irritated in your stomach once you take a drug, you should opt for enteric coated drug.

It’s perfect for acid-sensitive or delayed release formulation. Your decision is based on the properties of your drug, the goal of your therapy, and the preferred location of release. In all cases, refer to pharmaceutical formulation requirements to make the best decision.

Conclusion

Comparing enteric and film coating will enable you to make informed decisions in terms of solubility, protection, and timing of drug release such that your formulation addresses both therapeutic and manufacturing goals adequately.

More resources:

Film coating system – Source: SAINTYCO

Capsule Coating – Source: CAPSULEFILLER