The present invention relates to the field of anti-viral active agents, particularly to salts, more particularly to a maleate salt of the free base of N-[5-(aminosulfonyl)-4-methyl-1,3-thiazol-2-yl]-N-methyl-2-[4-(2-pyridinyl)-phenyl]-acetamide, to pharmaceutical formulations thereof as well as to methods for the production of these salts. The present invention also relates to the use of theses salts and of respective pharmaceutical formulations thereof in methods of treatment and/or prevention of human herpes simplex virus infections, particulary infections caused by HSV-1 and HSV-2.本發明係關於抗病毒活性劑領域、特定地N-[5-(胺基磺醯基)-4-甲基-1,3-噻唑-2-基]-N-甲基-2-[4-(2-吡啶基)-苯基]-乙醯胺之游離鹼之鹽、更特定地順丁烯二酸鹽、其醫藥調配物以及產生該等鹽之方法。本發明亦係關於該等鹽及其各別醫藥調配物在治療及/或預防人類單純疱疹病毒感染、尤其由HSV-1及HSV-2引起之感染之方法中之用途。