The Obsolescence of Hydrophilic–Lipophilic Balance: Interfacial Coverage, Electrostatic Reserve, and Mechanistically Partitioned Payload Ceilings in a Tri-Domain Delivery Architecture

Hydrophilic–Lipophilic Balance (HLB) has governed cosmetic emulsion design for seven decades. This paper argues that its continued use as the primary design framework for high-performance topical systems is no longer technically defensible, and advances a specific replacement: a tri-domain nano-colloidal architecture (NanoBase™) in which stabilization is treated not as a binary pass/fail condition but as a conserved, budgeted reserve consumed by downstream payload. The practical consequence is architectural modularity within a computable envelope: because every downstream addition draws against a reserve of known size, payload may be added, exchanged, or re-specified without re-deriving the emulsifier foundation.

Four arguments are made: HLB is a lossy scalar projection of a multidimensional interfacial problem; it is formally silent on deposition, the observable that governs topical efficacy; HLB-based development is structurally a local-minimum search because the framework provides no conserved quantity to price an addition; and its characteristic pathologies (overdose compensation, bolt-on encapsulation, barrier-disrupting penetration enhancement) are all workarounds for that single structural absence. The architecture supplies the missing quantity: interfacial coverage is fixed at manufacture, expanded by downstream oil as a two-thirds power law, derated by water-soluble payload, and bounded below by a critical floor, yielding a single feasibility inequality that replaces required-HLB matching. Peptide capacity resolves into three mechanistically independent ceilings (coverage-bound, ionic-strength-bound, and bilayer-leaflet-saturation-bound); lipid loading resolves into two orthogonal axes (cold-partitioning kinetics and Ostwald ripening susceptibility). Multi-angle dynamic light scattering from a first-bench build is presented at two timepoints as an architectural fingerprint. Falsification criteria are stated explicitly, and the central deposition claim is reported as not yet tested for this lineage. This work continues and extends the framework of DOI 10.5281/zenodo.18616576.