By delivering drugs slowly and steadily, sustained release formulations have revolutionized drug delivery through the controlled or gradual release of active ingredients over an extended period of time. Immediate-release medications also have potential for multiple dosing during the day, while sustained release treatments allow continual exposure of drug without peaks and troughs in medication levels. For instance, a 24-hour sustained release tablet may have no more effect than immediate-release medication dosing every 4—6 hours but might be expected to improve patient adherence and rates of missed doses.
Sustained release enhances drug efficacy as it provides a steady-state concentration in blood and minimizes peak-and-trough effects (41). In chronic conditions (eg, hypertension, diabetes), maintaining relatively constant blood levels of medicine can have a marked effect on patient outcomes. A study from The Journal of Clinical Pharmacology noted that patients taking sustained release drugs had a 20% decrease in adverse effects compared to those taking traditional immediate-release varieties, which further supports the benefit of using steady drug levels to limit side effects.
The pharmaceutical industry considers sustained release to be an important advance especially for short half-life drugs which require frequent dosing, it is ideal as it allows reduced frequency of administering the drug. Metformin, a very common drug used for type 2 diabetes is a good example. The sustained-release form has been shown to increase glycemic control without the gastrointestinal side effects often noted with the immediate-release formulation. The 25% reduced risk of gastrointestinal disturbance seen with sustained release metformin compared with patients in clinical trials has important implications for patient convenience and compliance.
Furthermore, the technology that is required to manufacture sustained release drugs such as polymer-based matrix systems which dissolve slowly to provide controlled drug delivery. This reduces how often the medicine needs to be administered, which sounds more user-friendly for patients and ultimately increases treatment efficacy. Not only is it more effective and patient-friendly, but sustained release systems are the basis of modern medicine; Dr. Robert Langer from MIT stated years ago that "Controlled drug delivery represents one of the greatest advances in medical treatment, providing new therapeutic opportunities."
In a 2020 Medscape survey, almost two-thirds of patients (64.5%) indicated that they preferred slow-release to wake up less at night needed to take their medications and the generally lower doses taken per day supported patient adherence rates [8]. Sustained release formulations increase patient adherence and therefore better long-term health outcomes (importantly, in diseases demanding a treatment over lifetime).
If you want to know more about how sustained release affects the potency of a drug then click on what is sustained release.
