The relevance of solid form in drug development has been well established over time. To fully understand drug properties, attention has been paid to solid state structure of drug mols. and their relationship to the drug formulation. While each drug developer has had their own strategies and workflows for screening and choosing solid forms of drug mols., the industry is aware of instances where "the best laid plans" often go awry. Specifically, more than two years after Norvir was brought to market, Abbott announced that deliveries of the capsules were suspended due to a problem affecting the solubility of the active substance. A new form had appeared: one that was less soluble than the marketed form. Attempts to eliminate Form 2 were performed, but the efforts were to no avail. In the end, there was no choice but to adapt to the new environment centered around Form 2. The following presentation presents how to use crystal structure prediction with lab-based tools to avoid the next Ritonavir.