DSC has gained quite a lot interest in drug purity investigation because it requires samples with low quantity (1–2 mg) and is considerably fast in terms of analysis time. For instance, by monitoring the effects of foreign substances, it can be found to what extent a drug is pure. It turns out that impurities decrease the melting temperature formula_7 of the drug. In addition, melting temperature can also be used to estimate the thermal stability of drugs, because the higher the formula_7 the more stable is the protein. Therefore, DSC allows instant monitoring of this temperature leading to much easier and faster way of controlling the drug quality.