prolongedrelease

Prolonged-release, often written as prolonged-release or, more commonly, extended-release, refers to pharmaceutical formulations designed to release an active drug over an extended period after administration. The goal is to maintain therapeutic drug levels with fewer doses, improving patient adherence and reducing peak-related side effects.

Common modalities include extended-release (ER), sustained-release (SR), controlled-release (CR), and delayed-release (DR). Technologies used to achieve prolonged release include matrix systems with a slowly dissolving polymer, coated beads or pellets with rate-controlling coatings, osmotic and diffusion pumps, and erodible or diffusion-controlled matrices that release drug gradually along the gastrointestinal tract.

The approach seeks to smooth the plasma concentration-time profile, avoiding high peaks and low troughs. Suitability depends on the drug’s solubility, stability, permeability, half-life, and site of absorption, as well as therapeutic needs and patient factors.

Advantages include improved convenience, steadier exposure, and potential reductions in adverse events linked to peak concentrations. Limitations include that not all drugs are appropriate for prolonged release, risk of dose-dumping if the product is damaged or crushed, higher manufacturing complexity and cost, and the need for appropriate patient selection, dosing accuracy, and monitoring.

Examples of prolonged-release products include metformin XR, amlodipine SR, extended-release methylphenidate, and certain antibiotics formulated for extended release.

Regulatory considerations emphasize consistent in vitro release, robust pharmacokinetic data, clear dosing instructions, and labeling that addresses safety, potential interactions, and misuse risks.