Direct imaging of the dissolution of salt forms of a carboxylic acid drug

Publication date: Available online 20 September 2018Source: International Journal of PharmaceuticsAuthor(s): Kofi Asare-Addo, Karl Walton, Adam Ward, Ana-Maria Totea, Sadaf Taheri, Maen Alshafiee, Nihad Mawla, Antony Bondi, William Evans, Adeola Adebisi, Barbara R. Conway, Peter TimminsAbstractThe optimisation of the pharmaceutical properties of carboxylic acid drugs is often conducted by salt formation. Often, the salt with the best solubility is not chosen due to other factors such as stability, solubility, dissolution and bioavailability that are taken into consideration during the preformulation stage. This work uses advanced imaging techniques to give insights into the preformulation properties that can aid in the empirical approach often used in industry for the selection of salts. Gemfibrozil (GEM) was used as a model poorly soluble drug. Four salts of GEM were made using cyclopropylamine (CPROP), cyclobutylamine (CBUT), cyclopentylamine (CPENT) and cyclohexylamine (CHEX) as counterions. DSC, XRD and SEM were used to confirm and characterise salt formation. IDR obtained using UV-imaging up to 10 min for all the salts showed that an increase in the chain length of the counterion caused a decrease in the IDR. Past the 10 min mark, there was an increase in the IDR value for the CPROP salt, which was visualised using UV-imaging. The developed interfacial (surface) area ratio (Sdr) showed significant surface gains for the compacts. Full dosage form (capsule) imaging showed ...
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research