Bixin Beyond Colour: Expanding Therapeutic Horizons Through the Integration of Pharmacological Potential with Modern Drug Design and Delivery Strategies

Bixin, a vibrant apocarotenoid derived from the seeds of <i>Bixa orellana</i> Linn. (commonly known as annatto), has been traditionally used as a natural colorant. However, recent advances have unveiled its diverse pharmacological and therapeutic potential, positioning it as a promising candidate in modern drug discovery and delivery systems. This review presents a comprehensive overview of bixin, encompassing its chemical structure, biosynthetic pathways, physicochemical characteristics, extraction techniques and novel nanodrug delivery systems. We critically examine its biological activities, including antioxidant, anti-inflammatory, anticancer, antimicrobial, neuroprotective, hepatoprotective, nephroprotective, and photoprotective effects, supported by mechanistic insights such as activation of the NRF2 pathway, suppression of STAT6 signaling, and modulation of oxidative stress and inflammatory mediators. Despite its wide-ranging bioactivities, the clinical application of bixin remains limited due to challenges related to its solubility, stability, and bioavailability. To address these limitations, innovative formulation strategies, including nanoparticle encapsulation, sustained-release systems, and polymer conjugates have been explored to enhance its pharmacokinetic profile and therapeutic efficacy. Majorly, field of nano-pharmaceutical technologies provides deep insights to overcome physiochemical challenges and enhance the therapeutic potential of bioactive agents. Nowadays, lipid-based nanodrug delivery approaches contribute in an efficient manner. Additionally, its integration into functional foods, cosmeceuticals, and photoprotective applications highlights its interdisciplinary relevance. This review uniquely bridges the gap between traditional knowledge and contemporary pharmaceutical science by consolidating current findings on bixin's pharmacological roles and delivery challenges. It also proposes future directions for translating bixin into a next-generation phytopharmaceutical through advanced formulation, mechanistic validation, and clinical evaluation. Collectively, the evidence positions bixin not merely as a natural colorant, but as a versatile bioactive molecule with significant promise in drug design, development, therapy, and delivery.