Loss on Drying (LOD) Test: Method, Pharmacopoeia Standards and Automated LOD Systems
What Is Loss on Drying (LOD)? Loss on Drying (LOD) is a gravimetric analytical method used to determine moisture content and volatile substances in pharmaceutical substances, excipients, finished dosage forms, food materials, and chemical products. The loss on drying method measures the weight reduction of a sample after drying under specified temperature conditions, typically 105°C unless otherwise defined in a monograph. The standard LOD test procedure involves: Accurately weighing the sample Drying at a prescribed temperature Cooling under controlled conditions Reweighing until constant mass Calculating percentage weight loss Because water and volatile matter directly affect product stability, potency, and shelf life, the loss on drying test remains a mandatory quality control parameter in regulated industries. Loss on Drying in Pharmacopoeias The loss on drying test is formally defined in major international pharmacopoeias: United States Pharma...