Extended Release Tablet Formulation: Challenges & Best Practices

For many pharmaceutical therapies it’s not enough to simply provide an effective drug, encase it in a tablet or capsule, and then call it a day. Getting the right dose and delivery is vital for effective treatment. For example, for patients with magnesium deficiency, a large single dose of this mineral won’t be fully absorbed by the body – a consistent, steady stream of it is much more effective.

That’s where extended release comes in. It allows pharmaceutical companies to not only spread out the delivery of the drug, but also target specific parts of the body for drug release. Most commonly it refers to time-dependent release in oral dose formulations. But designing a dose that can do this comes with challenges. This guide breaks down some of those challenges and describes best practices for dealing with them.

What Is Extended Release Formulation?

An extended release formulation is when a tablet or capsule is designed to release a drug in a controlled manner over a prolonged period of time after the dose is consumed by the patient. These dosages usually use hydrophilic or hydrophobic matrix systems, reservoir systems, multiparticulate, and osmotic release systems.

Advantages of Extended Release Formulation

Extended release in many types of drugs is helpful for three key reasons:

1. It improves patient compliance because a patient doesn’t have to remember to consume multiple pills over the course of a day. 

2. It reduces the "pill burden" on patients, or the negative psychological effect of taking lots of pills each day. 

3. It may reduce adverse side effects or even the risk of seizures by limiting the intensity of the drug after the initial dose.

Extended Release vs. Controlled Release vs. Sustained Release

Controlled release (CR) and sustained release (SR) both fall under the broader category of extended release – also known as modified release. Controlled release involves medication that maintains a constant release of the drug over a period of time. Sustained release, on the other hand, releases drug at a predetermined rate to maintain a constant drug concentration for a specific period of time with minimum side effects. 

SR medication is typically available in oral dosage forms, but CR medication can be administered into the body through other means besides oral dosage.

Delayed release (DR) is another form of modified release and these oral solid dosage forms are widely used to protect the gastric mucosa from irritating actives or to protect drugs sensitive to gastric fluids. For example, a drug meant to provide treatment to the small intestines would need to not release its active ingredient until it had reached this part of the body. They are designed for use on tablets or multiparticulate solid oral dosage products, including proton pump inhibitor (PPI) applications and enteric coated aspirin, which is widely taken.

Challenges for Extended Release Tablet Formulation

The most significant challenge facing the pharmaceutical industry when it comes to extended release is matching the release rate of the active pharmaceutical ingredient (API). Once a tablet is swallowed, the formulation must enable release of the active ingredient in the right amount and at the right intervals.

Effective tablet formulation and film coating are critical to successfully accomplishing the target release profile, and therefore pharma companies must choose the right formulation to ensure that the drug works as desired and help the patient to adhere to the treatment. This leads to better patient outcomes, and therefore more trust in the brand.

The main challenge for effective drug delivery that pharmaceutical companies face is ensuring that release is consistent and, where applicable, at the targeted site in the body. This requires a robust formulation along with reliable and reproducible manufacturing by an experienced production team to delivers a consistent, predictable result every time.

Best Practices for Extended Release Tablet Formulation

In order to ensure an extended release product that delivers consistent and predictable results, pharmaceutical companies should follow a few best practices to ensure they are creating the best possible product:

• Consider reducing the surface area of the API. This gives more control of delivery.

• Use matrix systems. Matrices involve mixing and compressing the API with a rate controlling excipient to slow the dissolution of the drug. Hydrophilic or hydrophobic polymers are good for this purpose. 
  
• Take advantage of modern film coating technologies. By using different polymers as coating agents, you can control the rate of dissolution of the API, or delay its release to be site specific. 
  
• Use an experienced excipient provider. A company with experience in formulation and manufacturing, along with high-tech facilities will help you to ensure the best results for your product. You need to access a partner with lab facilities that has proven it can deliver those results and is experienced and knowledgeable working with matrix systems and film coatings. At Colorcon, we have a dedicated technical team that has been tackling these challenges for decades. Contact us today for a consultation.