Why Sustained release, Immediate release, enteric-coated pellets?

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Why Sustained release, Immediate release, enteric-coated pellets?

By Aishwarya Salunkhe / June 16, 2025

Introduction:

An oral drug delivery system is essential for the safe and effective administration of pharmaceutical drugs to the patient. Drug delivery systems aim at an efficient modulation of therapeutic responses by delivering formulated drugs to the specific site of the body.

The delivery system plays an important role in increasing drug effectiveness and patient compliance, through the ease and comfort of medication intake.

To achieve the desired therapeutic effect, many medicated drugs require multiple dosages per day. To overcome this, various drug delivery systems can be incorporated, such as sustained release, immediate release, and enteric-coated release.

What Are Pellets?

Pellets are small spherical spheres or granules containing the active pharmaceutical ingredients, containing a protective layer safeguarding the active ingredients from the external environment, varying from 500 to 1500 microns for pharmaceutical applications.

Pharmaceutical manufacturers are showing more interest in pellets as dosage forms, whether filled into capsules or compressed into disintegrating tablets. The multiparticulate (pellets) offer several advantages over the traditional single-unit dosage forms.

The pellet size and shape ensure uniform drug dispersion in the GIT, reducing the risk of higher drug concentration and maximizing drug absorption. The spherical shapes show good flow properties with a narrow size distribution.

Sustained Release Pellets: Controlled Delivery for Better Compliance

Sustained-release pellets gradually release the active pharmaceutical ingredients in a controlled manner, allowing for prolonged drug delivery over an extended period of time. This profile is suitable for drugs that are metabolized too fast and eliminated too quickly from the human body.

The sustained-release profile of encapsulated pellets can modulate drug release, thereby aiding in maintaining a consistent drug concentration in the bloodstream.

These preparations offer many benefits, such as enhanced patient compliance due to decreased dosing frequency and fewer side effects associated with peak-trough fluctuations in drug levels. By ensuring constant drug concentration, sustained-release pellets improve therapeutic efficacy and can be of special value for treating chronic diseases.

Additionally, the technology in sustained-release pellets enables customized drug release profiles, taking into account the unique requirements of various drugs and patient groups. Their versatility is one of the reasons why they are a preferred choice by pharmaceutical companies seeking to maximize the efficacy and safety of their drug products.

With improved encapsulation technology, sustained-release pellets are further developed, and new avenues for innovative drug delivery systems are made possible to meet the needs of contemporary healthcare. With further research, we can expect even more complex formulations that improve patient experiences and outcomes further.

Immediate Release Pellets: Fast Action, Rapid Relief

Immediate-release pellets are designed to break down quickly and dissolve, ensuring rapid release of the active pharmaceutical ingredient (API). Immediate-release dosage form pellets help manufacturers expand their product range and enhance customer convenience.

IR pellets improve patient compliance, enhance stability, solubility, and bioavailability, and offer convenience, allowing for a high loading concentration of the active ingredients.

Immediate-release pellets are particularly useful where a fast onset of action is required. This formulation is perfect for drugs that need to act quickly, such as analgesics or some anti-inflammatories. The rapid disintegrating and dissolving process ensures efficient absorption of active ingredients, resulting in fast therapeutic action.

Furthermore, immediate-release pellets can be customized to an exact dose, thereby minimizing the possibility of over- or under-dosage. This high accuracy is important in achieving reliable outcomes in treatment and increasing patient satisfaction.

The development of IR pellets aligns with the increasing consumer interest in convenient and efficient healthcare products. Incorporating modern encapsulation methods allows for the production of resistant and performant pellet formulations suited for a wide range of patients. With advancing technology, one can anticipate new developments aimed at providing more efficient and attractive immediate-release medication.

Enteric-Coated Pellets: Targeted Delivery to the Intestine

Enteric-coated drugs are those medications that bypass the stomach and release the active ingredient into the small intestine. Enteric coating prevents the active pharmaceutical ingredient from early release into the acidic environment of the stomach.

Enteric-coated pellets offer various advantages over traditional enteric-coated tablets. They offer a quicker onset of action and faster release than enteric-coated tablets, thanks to their smaller size and larger surface area. They also decrease the retention time of the acid-sensitive drugs in the stomach, thereby protecting them from gastric degradation.

A prolonged residence time in the stomach can compromise the coating of the dosage form. There are two methods for preparing core pellets. The first involves mixing the drug with excipients and extruding to form pellets. In the other method, the drug is first layered onto neutral excipient pellets, which are then coated with an enteric layer to control where the drug is released.

Key Differences: Immediate Release vs Sustained Release vs Enteric-Coated Pellets

Immediate Release (IR) pellets are specifically developed for immediate release of the active drug upon administration, usually in the stomach or upper gastrointestinal tract.

Sustained Release (SR) pellets are designed to release the active pharmaceutical ingredient (API) slowly over a prolonged period to maintain therapeutic activity.

Enteric-Coated (EC) pellets are formulated to prevent drug release in the stomach and release the drug in the intestine, where stomach acid is not present.

Umang Global Group offers sustained-release encapsulated pellets, including mesalamine SR pellets, diclofenac sodium SR pellets, indomethacin SR pellets, nicardipine SR pellets, and ferrous sulphate SR pellets.

They also offer enteric-coated pellets such as pancreatin EC pellets, simethicone EC pellets, and proton pump inhibitors including omeprazole EC pellets, pantoprazole EC pellets, rabeprazole EC pellets, lansoprazole EC pellets, and dexlansoprazole EC pellets.

Umang Global Group offers custom-made encapsulated pellets according to your requirements, from various particle sizes to release profiles.

Reference

Mihir K Raval, Riddhi V Ramani, Navin R Sheth, Formulation and evaluation of sustained-release enteric-coated pellets of budesonide for intestinal delivery, Recent Patents on Drug Delivery & Formulation, [83 - 90], Volume 13, Issue 2, 2019.

Hetal Patel and Mukesh Gohel, A review on enteric-coated pellets composed of core pellets prepared by extrusion-spheronization, International Journal of Pharmaceutical Investigation, October 2013, Vol 3, Issue 4.

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