Loss-on-DryingTest
AboutLossonDryingofDrugs
Loss-on-drying(LOD)isdeterminedbyheatingasampleinanoventoatemperature belowitsmeltingpointandincludesallvolatilesubstances,includingwatercontent andsolvents.Lossondryingisanon-specificanalyticaltechniquethatremovesnot onlywaterfromthesample,butalsoallothervolatileimpuritiessuchasalcohol.The degreeofdryingdependsontemperatureanddryingtime.analysisofthetotalwater contentofanLODordrugproductcanincludebothboundwater(e.g.hydratedwater) andfreewater.Sinceothervolatileimpuritiesmaybepresentinthedrug,e.g.,alcohol; all,theLODmaybehigherthanthewatercontent.
%LODcheckformula:
Loss-on-DryingTestMethod
Oven
Onceplacedinaroomorconvectionoven,thesampleisrepeatedlyweighed accordingtoapresetscheduleandtheweightlossisrecordedOncetheweight remainsconstant,thedifferencebetweentheinitialweightandthefinalweightis calculated,correspondingtotheevaporatedmoisture.Thisisusedtocalculatethe percentageofmoisture.
MicrowaveDrying
Thisisanotherweightmethodthatusesseveralstepstodrythesamplewhile performingrepeatedweightmeasurementsMicrowaveheatingandevaporationofthe moistureinthesampleisveryfastandtakesonlyafewminutesInaddition,the samplesizedoesnothavetobeverysmall.
InfraredDrying
Infraredradiationorheatcanalsobeusedtodeterminethemoisturecontentofa sample,butonlyforsmallsamplesweighing0.1to120grams.
MoistureMeters
Moisturetesterisadevicefordeterminingthemoisturecontentusingthe loss-on-dryingmethodandconsistsofaweighingandhalogenheatingunit.Itis suitableforqualitycontrolandproductionneedsinpharmaceuticalandchemical industries.
SOURCE:https://www.formulationbio.com/loss-on-drying-test.html