Alginate-based long-acting injectable formulations: recent advances, biomedical applications, and translational challenges

Currently, numerous short-acting formulations are prescribed to patients to administer various therapeutics, which requires repetition of dosage, that may lead to poor patient compliance. Long-acting injectables are such kind of controlled or sustained-release novel formulation that can be fabricated to deliver the active ingredients into the target area for a prolonged time, lasting days, weeks, or months after administration. Alginate-based long-acting injectable (LAI) formulations are comparatively new in the market. Alginate is a natural polymer and a polysaccharide obtained from brown seaweed and some special bacteria. The biocompatibility and biodegradability play an important role in long-acting injectable formulations. As a result, alginate-based LAIs may offer good biocompatibility and provide prolonged drug release, depending on the formulation design and drug release characteristics. Using the latest technology in LAIs can also control the immediate burst release of the active ingredients so that unwanted effects can be reduced. Relevant articles were taken from Google Scholar, Web of Science, and Scopus, covering studies published between 2000 and 2026. This review will focus on various latest technologies for the preparation of alginate-based LAIs and their mechanistic release profiles, and lastly, the applications and challenges toward the biomedical field will also be discussed. Short-acting medications can reduce patient compliance because of their frequent dosing. On the other hand, long-acting injectable formulations can release drugs in a controlled manner, decreasing the need for repeated administration. A natural, biodegradable polymer, alginate, is promising for developing this type of formulation. This study will concentrate on the current technologies used to manufacture long-acting injectable formulations based on alginate and their diverse mechanistic release profiles.