Magister Pharmaceuticae - MPharm / Terizidone (TZD) is considered an essential anti-tuberculosis drug and in South Africa it is prescribed as part of the multi-drug resistant tuberculosis (MDR-TB) treatment regimen. From a literature study it became apparent that very little is known in terms of the physicochemical characteristics of TZD and only one literature source mentions one polymorphic form of this drug. Furthermore, it exhibits neurotoxicity as an adverse effect, leading to the concomitant administration of pyridoxine (PDX) to counteract the TZD-induced side effects. MDR-TB patients experience major side effects from taking the drug for a long period (18 months) and it often results in resistance and poor adherence. This study therefore focused on the possibility to combine TZD and PDX either as co-crystals or as co-amorphous solid-state forms. In order to achieve this a complete physicochemical profile of TZD was determined, since very limited information could be found in literature.