| abstract |
The present invention relates to a pharmaceutically acceptable acid addition salt of: (i) 9,10-dimethoxy-2-(2,4,6-tri-methylphenylimino)-3-(N-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one (RPL554); and (ii) ethane-1,2-disulfonic acid, ethanesulfonic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, hydrochloric acid, hydrobromic acid, phosphoric acid or sulfuric acid. |