A revision guide for crystalline pharmaceuticals to help you score top marks (MPharm or PharmD)

[@heidielliott5733]

Thank you SO much for adding that bit about habits- I was struggling to understand the relationship between unit cell and habits and now it is very clear! Carpark analogy helped a lot! Yay!

[@PharmaDrama]

That's good to hear - I like a good analogy

[@shigangruan8101]

Melting point can not determine the Gibbs free energy directly. So sometimes, the higher melting point polymorph can be meta-stable form at certain temperature.

[@MarkCimorelli]

❤❤❤Thank you so much

[@sayanpal9491]

if the solubility of the stable form is below industry standard, what to choose for formulation ? if you choose a metastable form, it might transition into a stable form with time. What is the best practice ?

[@PharmaDrama]

Yes, that is a tricky question. I guess the answer depends on whether you get enough bioavailability for your active. If not then a metastable form is an option but I think most companies would go with the stable form and use an alternative solubilisation strategy (eg milling, salt formation or mixing in an amorphous polymer).

[@sayanpal9491]

@@PharmaDrama : Thank you for response. Your channel was very helpful in brushing up my pharmaceutical crystallization knowledge.