Melatonin oral thin film (OTF) formulas balance three priorities: rapid disintegration, pleasant mouthfeel, and assay/stability. A typical formula combines:
Film-forming matrix: HPMC, PVA, PVP, pullulan — builds the film body and governs strength, clarity, and dissolution rate.
Plasticizers: glycerin, sorbitol, PEG 400 — add flexibility and crack resistance during storage/transport.
Active ingredient (API): melatonin — dispersed or partially dissolved in the matrix for fast sublingual/oral release.
Wetting/surface-active agents: e.g., polysorbate 80 — improve wetting and dissolution, reduce aggregation.
Flavors & sweeteners: flavorings, sucralose, acesulfame K, erythritol — mask bitterness/aftertaste and improve adherence.
Acidulants/buffers: citric acid / sodium citrate — refine taste and stabilize pH to support melatonin stability and release.
Antioxidants/stabilizers: ascorbic acid, trace EDTA — slow oxidation and extend shelf life.
Colorants (optional): for flavor/dose differentiation; must comply with regulations.
Beyond formulation, high-barrier unit sachets (e.g., aluminum–polymer laminates) are essential to limit moisture and oxygen ingress, preserving melatonin content and mouthfeel.