biostudies-literatureUnknown13(1)Qiu FBinding of therapeutics to proteins in blood plasma is important in influencing their distribution as it is their free (unbound) form that is able to cross cellular membranes to enter tissues and exert their actions. The concentration and composition of plasma proteins vary during pregnancy and development, resulting in potential changes to drug protein binding. Here, we describe an ultrafiltration method to investigate the extent of protein binding of six drugs (digoxin, paracetamol, olanzapine, ivacaftor, valproate and lamotrigine) and two water soluble inert markers (sucrose and glycerol) to plasma proteins from pregnant and developing rats. Results showed that the free fraction of most drugs was lower in the non-pregnant adult plasma where protein concentration is the highest. However,Scientific reports1266https://www.ebi.ac.uk/biostudies/studies/S-EPMC9870879biostudies-literatureDevelopmental changes in the extent of drug binding to rat plasma proteins.PMC9870879Dziegielewska KMHuang YQiu FFitzpatrick GSaunders NRHabgood MDfalseDevelopmental changes in the extent of drug binding to rat plasma proteins.Binding of therapeutics to proteins in blood plasma is important in influencing their distribution as it is their free (unbound) form that is able to cross cellular membranes to enter tissues and exert their actions. The concentration and composition of plasma proteins vary during pregnancy and development, resulting in potential changes to drug protein binding. Here, we describe an ultrafiltration method to investigate the extent of protein binding of six drugs (digoxin, paracetamol, olanzapine, ivacaftor, valproate and lamotrigine) and two water soluble inert markers (sucrose and glycerol) to plasma proteins from pregnant and developing rats. Results showed that the free fraction of most drugs was lower in the non-pregnant adult plasma where protein concentration is the highest. However,2023-01-01T00:00:00Z2023 Jan2025-04-04T18:53:30.897Z2025-04-04T18:53:30.897ZS-EPMC98708793669071110.1038/s41598-023-28434-1