Establishment of In Vitro Dissolution Based on Similarity with In Vivo Dissolution: A Case Study on Aripiprazole

In vitro dissolution that predicts the in vivo performance of solid preparations is extremely important in formulation optimization. Fraction absorbed (Fa) has been used to screen in vitro dissolution protocols based on the idea of in vitro–in vivo correlation (IVIVC) but failed to increase the success rate due to the inaccuracy of the Fa. The essence of IVIVC is the correlation between in vitro dissolution and in vivo dissolution. We tried to establish in vitro dissolution protocol via similarity with in vivo dissolution using aripiprazole (APZ) as a model drug. Hybrid APZ crystals (APZ-HCs) were prepared by physically embedding aggregation-caused quenching (ACQ) fluorophores inside the lattice to measure the in vivo dissolution. The process did not change the physicochemical properties and crystallinity of APZ. The fluorophore illuminated APZ crystals but was quenched upon dissolution of APZ-HCs in aqueous media, enabling monitoring intact APZ-HCs in real-time. The good correlation between fluorescent quenching and dissolution of APZ-HCs justified reliable quantification of intact APZ crystals. The residual percentage of fluorescence intensity in rats treated by APZ-HCs was recorded with time, which was converted to in vivo dissolution by the difference from 100%. The in vivo dissolution was validated with the Fa. The in vitro dissolution profile of APZ was set up via a similarity factor larger than 50 in comparison with the in vivo dissolution. The study provides a novel idea and method to establish in vitro dissolution protocol.