Sustained Release and Prolonged Release Tablets and their Difference : Pharmaguideline

Online GMP Courses with Certificate


Sustained Release and Prolonged Release Tablets and their Difference

Both of these are delayed release tablets having different properties in their drug release timings but have considerable differences.
The words sustained release and prolonged release can be used interchangeably because they mean the same thing. But the difference between sustained release tablets and prolonged release tablets is surely evident.

Sustained Release Tablets

Sustained release tablets are in the form of dosage where a drug is administered to a patient at a given or calculated rate with the aim of maintaining a certain concentration of the administered drug over a specific period of time in the patient's system while reducing possible side effects.

Sustain Release Tablets

Prolonged Release Tablets

Prolonged release tablets are meant to affect after some time from the moment they are administered and they are known to be released in small portions over a long period of time with no specifications to time or rate of concentration.

Difference between Sustained Release and Prolonged Release Tablets

Sustained release tablets are more of a controlled release. This happens when a capsule is made and is filled with other small pellets of drugs with different coatings that will not dissolve immediately once they are administered but will take time to release their contents at a predetermined rate.

While prolonged release tablets and capsules are aimed at delaying administration and dissolve at a slower and constant rate into the body system with the benefit of not having to take the drugs more frequently. This is mostly for patients with chronic illness they are able to take drugs less number of times a day.

Prolonged release in oral dose formulations is mostly time-dependent and delayed release. Often prolonged release is targeted and intended to heal certain areas of the body system that can not be cured effectively by other ordinary drugs and ointments. This is different with the sustained release tablets as they are often administered slowly to maintain a particular amount of drug levels into the bloodstream during a drug administration or injection so as to maintain an efficient healing process.
Related: Solid Pharmaceutical Dosage Forms - Tablets

Mostly prolonged release tablets are administered to heal certain parts or target body parts. Once they are introduced into the blood system they are released either on the specific part or near the target site that needed the cure. While the sustained release does not target particular body sites or parts.

Sustained release tablets are often time-release drugs, they can either be released immediately or in small amounts after administration. They include pills and capsules. Time and rate of administration of the formulations are predetermined so as to reduce the effect on blood levels or reduce effects on the intestinal tract and even extend the drugs half life.

This is not the same with prolonged release formulations as the drugs administered are meant to prolong their effectiveness into the bloodstream. This has the advantage of less administration of drugs, improved healing process as patients comply when taking drugs less number of times and also the benefit of a constant blood level.

However prolonged release drugs in some cases may fail to be completely absorbed into the blood system thus causing chronic diseases to recur eg stomach disorders, also prolonged-release tablets in most instances are more expensive than ordinary and other drugs thus they might not be affordable to patients who are not financially stable.

Frequently Asked Questions on Sustained and Prolonged Release Tablets

Q: What are sustained-release tablets?

Sustained release tablets are also known as extended release tablets or controlled release tablets. These tablets have controlled release of the active component over an extended period of time. Due to this controlled and slow release allows a prolonged drug effect and also reduces the dose frequency.

Q: What are prolonged release tablets?

Prolonged release tablets are very similar to sustained release tablets with a difference of not having the control on the concentration of drug in the body.

Q: How do sustained-release tablets work?

Sustained release tablets work on various mechanisms that depends upon the type of formulation used. Generally, polymer binders and tablet coating are used to control the tablet drug release. These methods are used to ensure the consistent and controlled drug release.

Q: What are the advantages of using sustained-release tablets?

Sustained release tablets has various advantages including reduced dose frequency, provide consistent drug concentration in the body, maintain thraoutic level of drug and minimize the dose concentration fluctuation in the body.

Q: What factors are considered when formulating sustained release tablets?

Severy factors are considered during the formulation of sustained released tablets including pharmacokinetics of the drug, appropriate polimer compatibility of the drug with excepients and desired release profile of the tablet.

Q: How are sustained release tablets evaluated for quality and performance?

Sustained release tablets undergo various tests to evaluate the performance and quality including drug release kinetics, dissolution profile, stability, content uniformity and physical parameters. Dissolution test is generally used to evaluate the drug release and consistency of the released drug from the tablet.

Q: Can all drugs be formulated as sustained release tablets?

No, all drugs are not suitable for sustained release formulation. Certain drugs have narrow therauptic index and require immediate release for optimal effect. Some drugs have specific release requirements that can not be achieved by the sustained release formulation. Each drug is required to evaluate individually to determine their suitability for sustained release formulation.

Q: Are there any disadvantages or limitations to sustained release tablets?

Sustained release tablets have several advantages but these have some disadvantages including slower therapeutic effect in comparison with immediate release tablets and it has complex formulation and higher manufacturing cost. Additionally, all drugs can not be formulated as sustained release tablets.

Q: Are sustained release tablets and extended-release tablets the same thing?

Yes, sustained release and extended release both terms are used for the controlled release tablets. These tablets release the active ingredients gradually for a extended period of time.

Ankur Choudhary is India's first professional pharmaceutical blogger, author and founder of, a widely-read pharmaceutical blog since 2008. Sign-up for the free email updates for your daily dose of pharmaceutical tips.
.moc.enilediugamrahp@ofni :liamENeed Help: Ask Question

4 comments: Post Yours! Read Comment Policy ▼

  1. meaningful and specified. thanks sir

  2. Very clear understandable. Thanks!

  3. Thank u very much, very clearly described.👍🏻


Please don't spam. Comments having links would not be published.

Popular Categories

QA SOPs QC SOPs Micro SOPs HVAC Production SOPs Stores SOPs Checklists Maintenance SOPs HPLC Sterile GLP Validation Protocols Water System GDP Regulatory Maintenance Calibration Warning Letters Education B.Pharmacy
Online Courses

Follow Pharmaguideline



Editable Pharmaceutical Documents in MS-Word Format. Ready to use SOPs, Protocols, Master Plans, Manuals and more...



Recent Posts