A COMPREHENSIVE REVIEW ON OLFACTORY DELIVERY OF HERBAL BIOACTIVES: SCIENTIFIC APPROACHES TO FORMULATE HERBAL ANTI-STRESS INHALER

The review highlights the strong potential of olfactory delivery for administering herbal bioactives, a potential route characterised by its rapid onset of action and broad patient acceptability. This therapeutic relevance is primarily linked to the direct connection between the olfactory system and the limbic system; a vital brain region is responsible for modulating emotional regulation and stress responses. The paper demonstrates recent scientific evidence on how aromatic phytochemicals, mainly terpenoids and phenolic compounds present in essential oils, interact with olfactory receptors to effectively influence neural pathways involved with stress, anxiety, and mood regulation. It also identified Primary herbal selection used in anti-stress inhalers is determined, as well as the essential analytical techniques required for profiling these volatile constituents are to ensure quality control. Along with the review focuses on various formulation approaches, including essential oil blends, nano-emulsions, nasal aromatherapy sticks, and solid-inhaler systems, emphasis is placed on optimising key aspects such as the stability, safety, and efficiency of volatile release. By carefully selecting the appropriate ingredients, adjusting concentration, and delivery mechanism. This review also highlighted the anxiolytic and stress-reducing effects resulting from olfactory exposure, thereby consolidating advancements in phytochemistry, delivery systems, and neuroscientific mechanisms to provide a robust scientific foundation for the rational design of optimized herbal anti-stress inhalers.