Liraglutide, a potent glucagon-like peptide 1 (GLP-1) analogue, is one of the most common treatments for type 2 diabetes mellitus (T2DM) patients. Liraglutide selectively binds to GLP-1 receptor and enhances the secretion of insulin, which is a hormon...
Liraglutide, a potent glucagon-like peptide 1 (GLP-1) analogue, is one of the most common treatments for type 2 diabetes mellitus (T2DM) patients. Liraglutide selectively binds to GLP-1 receptor and enhances the secretion of insulin, which is a hormone to maintain an appropriate level of sugar in the human body. This study aimed to develop an extended design of experiment (DoE)-in vitro in vivo correlation (IVIVC) model that defines the relationship between the formulation composition, in vitro release, and in vivo pharmacokinetics of liraglutide. The sustained-release (SR) liraglutide injectable formulations were designed by applying DoE with the factors of lecithin, span 80, and benzyl alcohol. The in vitro release profile was determined by the test tube method. The maximum rate of drug release based on Michaelis-Menten kinetics (Vmax) was obtained to describe the effects of the sustained-release injectable formulations. DoE model was validated by comparing observed and predicted 1/Vmax, and the prediction error (PE%) was 1.40%. In vivo pharmacokinetics of three types of liraglutide SR injectable formulations (1 mg per injection) with different release rates were determined in SD rats. To estimate the in vivo release of liraglutide, a population pharmacokinetics (POP PK) model was developed, and level A IVIVC was established for liraglutide SR injectable formulations. Finally, by connecting the DoE model and IVIVC model, the extended DoE-IVIVC model has been established. Utilizing the extended DoE-IVIVC model, prediction of the in vivo pharmacokinetic parameters from the formulation composition could be performed. The extended IVIVC model was validated by comparing the observed and predicted maximum concentration of liraglutide in the plasma (Cmax) and the area under the plasma concentration vs. time profile (AUC), which were derived from internal validation. PE% was 0.77% to 4.44% for Cmax and 1.03% to 8.14% for AUC, satisfying the FDA criteria for the predictability of IVIVC. Applying the extended DoE-IVIVC model, the development of SR injectable formulations to acquire an optimal pharmacokinetic profile would be performed efficiently.