Dissolution

This chapter aims to demonstrate the value of dissolution within biopharmaceutics and to highlight the types of apparatus used to better understand the mechanisms associated with drug product dissolution and the interplay with gastrointestinal (GI) physiology. Solubility refers to the capacity of solute to dissolve into a solvent and is measured at equilibrium conditions where the maximum solute is dissolved. Convolution is the process of obtaining/predicting a pharmacokinetic profile for a drug from the dissolution data, whilst deconvolution is the opposite that is, extracting the dissolution profile from the pharmacokinetic data. Dissolution apparatus has closely controlled agitation rates either via rotation of the paddle or basket or by controlling the dip rate or fluid flow. Advances based on compendial apparatus and using novel systems have provided biorelevant testing systems to better replicate conditions within the GI tract.