Determining the solubility of active substances in an artificial intestinal juice in 96-well plate

Title

Oral presentation

Description

Yoana Petrova, Zahari Vinarov, Nikolay Adamov, Slavka Cholakova
Department of Chemical and Pharmaceutical Engineering, Faculty of Chemistry and Pharmacy, Sofia University "Saint Kliment Ohridski"

Subject

1.The study of the solubility of hydrophobic active substances (AS) in artificial intestinal fluids (IF) is of interest to the pharmaceutical industry. Measuring this solubility is difficult due to limited amounts of AS during early pharmaceutical development. The aim is to develop a method for determining the influence of the composition of IF on fasted and fested state in a 96-well plate, which renders working with small amounts of AS and simultaneously examining a large number of parameters and/or AS. 2.A commercial mixture of sodium taurocholate and lecithin to which saturated (monopalmitin and palmitic acid) or unsaturated lipids (monoolein and oleic acid) were added was used to model IF. The usefulness of the method was tested with 14 AS whose solubility in IF was measured after 24h of stirring at 37℃, centrifugation and analysis by high performance liquid chromatography-HPLC. 3.A number of obstacles relayed to the implementing of the procedure were overcome.3-6mg of AS was added to each well of the plate volumetrically using a calibrated micro-spoon.Clogging of the pipette when adding the state was prevented by filtering it beforehand. Effective separation of excess undissolved substance was achieved by centrifugation at 20 000 x g. Using the developed procedure, the solubility of 14 AS in 6 types of model IF (3 fasted and 3 fested) was determined in quadruplicate (n=4):а total of 334 experimental points were obtained. 4.The method was successfully used to determine the solubility of AS in model IF in a 96-well plate,allowing working with small amounts of AS and high efficiency. The solubility of most AS improved with unsaturated lipids and with an increase in the concentration of taurocholate and lecithin-after a meal.
Keywords: solubility, artificial intestinal juice, 96-well plate