Extended-Release Buprenorphine

Overview

Extended-release buprenorphine refers to long-acting pharmaceutical formulations of buprenorphine—a partial mu-opioid receptor agonist—designed to deliver sustained therapeutic plasma concentrations over weeks to months from a single administration. Unlike daily sublingual buprenorphine-naloxone (Suboxone), these formulations eliminate the need for daily dosing and the associated risks of diversion, missed doses, and precipitated withdrawal. The primary approved indication is the treatment of moderate-to-severe opioid use disorder (OUD). Two principal delivery platforms have reached clinical use: subcutaneous injectable depots, most notably Sublocade (a PLGA-based in situ forming implant utilizing the Atrigel technology system), and long-acting injectable buprenorphine (LAIB) products such as Brixelle/Buvidal, which employ small-volume injectable depots administered weekly or monthly. By maintaining stable buprenorphine serum levels, extended-release formulations reduce cravings, suppress illicit opioid use, and minimize the peaks and troughs in plasma concentration that can complicate adherence with short-acting alternatives.

The pharmacological rationale centers on buprenorphine's high mu-opioid receptor affinity and slow receptor dissociation kinetics, which together produce durable opioid blockade and attenuation of withdrawal even at trough plasma levels achievable with monthly dosing. As a partial agonist with a ceiling effect on respiratory depression, buprenorphine retains a favorable safety profile relative to full agonists such as methadone, making extended-release delivery clinically viable without the cardiac monitoring burden associated with methadone. The shift toward injectable or implantable formulations represents a significant evolution in opioid substitution therapy (OST), addressing structural barriers to treatment retention that are particularly acute in rural, coastal, and underserved populations.

Focus of Latest Publications

Recent publications have examined extended-release buprenorphine from both clinical and formulation-development perspectives.

One study described a randomized controlled pilot trial of extended-release buprenorphine versus sublingual buprenorphine-naloxone in rural settings (RXR). The stated rationale was that the most recent formulation of injectable extended-release buprenorphine may improve treatment engagement and outcomes for people with OUD. This indicates ongoing interest in whether long-acting injectable delivery can address barriers common in rural care, such as access, retention, and medication adherence.

Several studies focused on long-acting injectable buprenorphine in real-world treatment settings. A retrospective cohort study from Cornwall, South West England, used treatment outcome profile data to examine outcomes among individuals receiving long-acting injectable buprenorphine in rural and coastal contexts. The publication framed long-acting injectable buprenorphine as a potential alternative to traditional treatments such as methadone, with possible benefits in adherence and outcomes. Another article, “The matter of mattering in depot buprenorphine treatment,” discussed long-acting injectable buprenorphine combined with social and health related interventions in a Danish clinic, highlighting the importance of treatment experience and service context in depot buprenorphine care.

Extended-release buprenorphine was also relevant to formulation science. A 2026 Journal of Controlled Release paper described the development of a compositionally equivalent buprenorphine in situ forming implant, identified as Sublocade, using a PLGA-based system designed for sustained delivery with monthly dosing for moderate to severe OUD. The study emphasized the product’s role as a sustained-release partial mu-opioid receptor agonist formulation. This work reflects continued optimization of depot delivery systems for buprenorphine.

In addition, the broader buprenorphine treatment landscape appeared in studies that are not exclusively about extended-release formulations but are relevant to its clinical context. A qualitative exploration from the HPTN 094 INTEGRA trial examined perceptions of buprenorphine-naloxone treatment and fear of precipitated withdrawal among participants and staff in a mobile unit delivering integrated MOUD and HIV services for people with OUD who inject drugs. Although this study centered on buprenorphine-naloxone rather than extended-release buprenorphine specifically, it is relevant because it addresses barriers to buprenorphine adoption in integrated care settings, including HIV infection-related service delivery.

Other publications addressed buprenorphine/naloxone in pain-related and palliative care contexts. A pragmatic Canadian multisite trial analyzed differential impacts of methadone and buprenorphine/naloxone on pain-related outcomes among people with non-heroin opioid use disorder, noting that both therapies have analgesic properties. A simulation-based curriculum for end-of-life crises and symptom management included initiation of buprenorphine-naloxone for cancer-associated pain in a patient with OUD. These studies reinforce the broader clinical relevance of buprenorphine-based therapies, including extended-release formulations, in settings where pain management and OUD treatment overlap.

Key Publications

NEWJul Perceptions of Buprenorphine With Naloxone Treatment and the Fear of Precipitated Withdrawal: A Qualitative Exploration With HIV Prevention Trials Network 094 INTEGRA Participants and Staff. (Drug and alcohol review, 2026, PMID 42322177): "This study examined participants' and staff perceptions of adopting and delivering buprenorphine-naloxone on a mobile unit providing integrated MOUD and HIV services for people with opioid use disorder who inject drugs in the HPTN 094 INTEGRA trial."
NEWJul Differential Impacts of Methadone and Buprenorphine/Naloxone on Pain-Related Outcomes Among People With Non-Heroin Opioid Use Disorder: Secondary Analyses From a Pragmatic Canadian Multisite Trial. (Drug and alcohol review, 2026, PMID 42313747): "In addition to their use as opioid agonist therapy (OAT), methadone and buprenorphine/naloxone also have analgesic properties."
Jul Emergencies in palliative medicine: novel simulation-based curriculum for end-of-life crises and symptom management. (BMJ supportive & palliative care, 2026, PMID 41871932): "(3) initiation of buprenorphine-naloxone for cancer-associated pain in a patient with opioid use disorder (OUD)"
Jun Exploring long-acting injectable buprenorphine in rural and coastal contexts: A retrospective cohort study of individuals' outcomes from treatment outcome profile data in an opioid substitution service in Cornwall, South West of England. (Drug and alcohol dependence, 2026, PMID 41946037): "Long-acting injectable buprenorphine (LAIB) offers a potential alternative to traditional treatments such as methadone, with possible benefits in adherence and outcomes."
Jun The matter of mattering in depot buprenorphine treatment. (The International journal on drug policy, 2026, PMID 42030759): "...long-acting injectable buprenorphine combined with social and health related interventions in a Danish clinic..."
May A systematic approach to develop and characterize a compositionally equivalent buprenorphine in situ forming implant (Sublocade®). (Journal of controlled release : official journal of the Controlled Release Society, 2026, PMID 41791460): "Sublocade® is a PLGA-based in situ forming implant designed for the sustained delivery of buprenorphine, a partial mu-opioid receptor agonist, with a monthly dosing regimen for the treatment of moderate to severe opioid use disorder (OUD)."
May Randomized controlled pilot trial of extended-release buprenorphine vs. sublingual buprenorphine-naloxone in rural settings (RXR): Study rationale and design. (Contemporary clinical trials, 2026, PMID 41850520): "The most recent formulation of injectable extended-release buprenorphine (XR-BUP) may improve treatment engagement and outcomes for people with OUD."