Abstract
Co-crystal forming abilities of the two anti-HIV drugs lamivudine and zidovudine were studied. A study of five crystal structures was carried out to investigate the general applicability of the retrosynthetic approach in the design of new co-crystals. This analysis of co-crystals and salt structures showed a complete to partial success, and in one case, a total failure to obtain the predicted synthon. Both screening strategies and rerrosynthetic methods may be appropriate for the discovery of new active pharmaceutical ingredients co-crystals.