In vitro models evaluate lipid-based drug delivery systems for enhancing solubilization and discharge of the drug. After ingestion, the food particles experience different physical and chemical changes that prompt their fragmentation into little pieces and change into less complex atomic groups that can be effortlessly absorbed into the blood. The dynamic mono and multi-compartmental models have become more advanced with in vivo information input. The Dynamic Gastric Model (DGM) has two sections: One is the body and the other is the antrum of the gastric. Up until now, TNO gastro-Intestinal Model-1(TIM-1) is considered to mimic the closest reproduction of the energy and flow of human retention. Pancreatic lipase, bile salts, phospholipids and calcium ions are involved in the intestinal lipolysis. The intestinal lipolysis is typically assessed by the rate and degree of free unsaturated fats discharged due to the activity of P-LIP. These can be estimated utilizing diverse strategies such as colorimetric enzymatic test, gas chromatography and pH-stat titration. The various in vivo pharmacokinetic aspects of LBFs are formulation and solubilization, dispersibility, dilution and effect on pharmacokinetics that have been described in this chapter. Other pharmacokinetic parameters including assimilation and bioavailability improvement, the impact of excipient choice on bioavailability, lymphatic transport and food effect reduction have been summarized. This chapter highlights the various in vitro digestion models and pharmacokinetic aspects of LBFs.