TY - JOUR T1 - The Biological Afterlife of Nanocarriers: A Mass-Balance Framework for Connecting Material Degradation, Persistent Fragments, Repeat-Dose Accumulation, and Long-Term Pharmaceutical Safety A1 - Laura Bianchi A1 - Michael Tan A1 - Julia Weber JF - International Journal of Pharmaceutical Research and Allied Sciences JO - Int J Pharm Res Allied Sci SN - 2277-3657 Y1 - 2026 VL - 15 IS - 1 DO - 10.51847/ibQluQxeqy SP - 191 EP - 201 N2 - Nanocarrier pharmacology is commonly characterized through circulating particles, delivered payloads, tissue signals, or therapeutic responses. These observables can disappear or change while constituent material undergoes redistribution, fragmentation, or biological transformation. Their time courses therefore provide incomplete answers to long-term material-fate questions. To develop a nonempirical, material-conserving theory explaining how carrier degradation, compartmental residence, immune history, and repeated exposure can follow interacting but non-synchronous clocks. Published studies of nanocarrier transport, chemical degradation, reporter stability, biodistribution, and repeat-dose immunity provide mechanistic constraints for a prospective accounting scheme. A chemically indexed constituent balance separates physical particle integrity from molecular persistence and analytical visibility. A multiple-clocks account links this balance to tissue residence and dose-history-dependent responses without presuming that residual fragments cause toxicity. The theory predicts different outcomes when chemical cleavage, tissue redistribution, immune priming, and successive administrations overlap. It requires orthogonal constituent measurements and comparisons against conventional pharmacokinetic and immune-mechanistic explanations. Durable safety claims demand evidence about what chemical material remains, where it resides, what has been recovered, and how the biological response changes with dosing history; the theory itself supplies testable propositions, not new longitudinal safety findings. UR - https://ijpras.com/article/the-biological-afterlife-of-nanocarriers-a-mass-balance-framework-for-connecting-material-degradati-bwkfj57dnjyvlfg ER -