PHC320H1 Lecture Notes - Lecture 37: Amorphous Solid, Eutectic System, Organic Acid Anhydride

• School: UTSG
• Department: Pharmaceutical Chemical Engineering and Applied Chemistry
• Course: PHC320H1
• Professor: Shirley Wu

Document Summary

Solid forms can grow and disappear and convert, and transport interconversion and transformation of solid form is when one solid form converts to another solid form. Interconversion can happen is between amorphous and crystalline form as well as anhydrate to hydrate/solvate and also among different polymorphs they can interconvert. Less stable means they will change to more stable form, which spontaneous process, thermodynamically driven process, if we grind or crystallize, we may obtain less stable ones. Ex: novobiocin prepared using amorphous form since crystalline form doesn"t give any efficacy. So prepared in aqueous suspension form with amorphous solid and slowly converts to crystalline form spontaneously gradually and bioavability decreases. Eutectic mixtures mix 1g of crystal a (mp 100 degrees0 and 1g of crystal b (mp60) so 2 gs mixture, mp is half half, only if we assume if not eutectic mixture, but if eutectic mixture it is wrong.