Clinical translation of long-acting drug delivery formulations

Most pharmaceuticals are given using short-acting formulations that require frequent administration, which can negatively affect patient compliance and increase failure risks associated with inconsistent use. By contrast, long-acting release formulations can achieve sustained release of drugs for weeks, months or years. In this Review, we discuss long-acting drug delivery formulations that release drugs for at least 1 month and that have received approval from the US Food and Drug Administration (FDA), with an emphasis on materials used in their formulation. We highlight different slow-release mechanisms, including dissolution-based, biodegradation-based (preformed and in situ-formed), non-degradable implantable and hydrogel-based formulations, and investigate the clinical applications of long-acting drug delivery formulations, including long-acting contraceptives, extended sex hormone suppression, opioid and alcohol addiction treatments and localized drug delivery to the eye. Finally, we summarize release mechanisms, delivery duration, pharmaceutical forms, administration routes, indications, manufacturers and inactive ingredients of 63 FDA-approved long-acting drug products. We conclude by looking at the future challenges and opportunities for long-acting drug delivery formulations.