Abstract

Chirag Warty, Dr. Manaswi Rajurkar*

ABSTRACT

Background: The lymphatic system represents a critical but underutilised determinant of drug pharmacokinetics, particularly for lipophilic and lipid-associated compounds.[1,2] While oral and conventional transdermal delivery routes primarily rely on capillary absorption followed by hepatic first-pass metabolism, lymphatic transport offers an alternative pathway characterised by delayed systemic entry, metabolic preservation, and prolonged tissue exposure.[1,8] Objective: This review presents a mechanistic framework for lymphatic pharmacokinetics arising from oil-based phytochemical delivery via the umbilical (Nabhi) region. By integrating principles from dermal transport biology, lymphatic physiology, lipid-based drug delivery, and interstitial fluid dynamics, we examine how Nabhi delivery may preferentially bias absorbed phytochemicals toward lymphatic rather than capillary uptake.[1-9] Evidence Summary: Lipophilic compounds delivered in triglyceride-rich or phospholipid-containing vehicles exhibit a consistent tendency toward lymphatic capture in the dermal interstitial space, producing delayed Tmax, reduced Cmax, extended apparent half-life, and attenuated hepatic first-pass extraction.[1,4,7,8] The periumbilical region possesses a dense superficial lymphatic plexus and structural features - including the umbilical scar connective tissue and prolonged formulation residence in the concave nabhi geometry - that further support lymphatic bias over vascular uptake.[2,5,6] Oil-based formulations, as used in classical Ayurvedic Nabhi Chikitsa, maintain phytochemicals in lipid-associated states conducive to lymphatic entry and slow aqueous diffusion, directly paralleling the physicochemical requirements established in the lipid-based drug delivery literature.[7,8,12-14] Conclusions: Lymphatic pharmacokinetics constitutes a plausible and mechanistically grounded feature of Nabhi-based phytochemical delivery. The resulting pharmacokinetic profile - attenuated peak concentrations, extended apparent half-life, and reduced hepatic metabolic loss - supports a reconceptualisation of bioavailability for traditional herbal oil-based systems and provides a non-clinical, systems-level foundation for future modelling and experimental validation.