Table 1. List of Coformers Used in Solid Form Screening, Their pKa Values, and ΔpKa Relative to CFZa.
coformers | pKa | ΔpKaa | abbreviation |
---|---|---|---|
hydrochloric acid | <−6 | 14.511 | HCl |
sulfuric acid | –3 | 11.511 | Sul |
nitric acid | –1.3 | 10.211 | Nit |
oxalic acid | 1.27 | 7.241 | Oxa |
phosphoric acid | 2.12 | 6.391 | Pho |
citric acid | 3.1 | 5.411 | Cit |
formic acid | 3.75 | 4.761 | For |
acetic acid | 4.76 | 3.751 | Ace |
pKa CFZ taken as 8.511, as determined at 37 °C.29