Biorelevant equilibrium solubility testing is a crucial biopharmaceutical parameter that determines the solubility of a drug in simulated (in vitro) gastrointestinal fluids. This provides valuable insight into potential for oral (in vivo) delivery and absorption.

Biorelevant solubility testing can be applied rapidly and accurately using high throughput screening (HTS) or conventional shake-flask methodologies.

To establish the equilibrium solubility of one or more early-stage candidates- such as during lead selection, biorelevant solubility filters, along with Biorelevant Mini Prep Kits, are designed to provide accurate solubility results by enabling ease filtration using less than 1mg of drug substance.

The filter design minimises the risk of filter bursting. Biorelevant solubility filters are robust and purpose-built to deliver accurate and reproducible results. Filter adsorption studies are not required as the drug saturates the filtering during the experiment.

Solubility filter components

The solubility filter has four main components.

• Cap with slit septum
• Filter housing
• Depth filter
• Vial

The polypropylene depth filter removes larger particles and being thicker and stronger than conventional membrane filters reduces the likelihood of filter bursting resulting in wastage or precious drug substance. The use small volume of biorelevant medium (about 0.5mL) and <1mg drug candidate in each solubility filter makes biorelevant solubility testing practical and compound sparing.

Download guide

Establishing biorelevant equilibrium solubility is a critical step supporting candidate selection and can provide valuable insight into potential formulation strategies. Download the step-by-step guides to help you set up the analytical method and conduct the Biorelevant equilibrium solubility test for your drug candidate.