Interactions between water and component materials take place in all steps of dosage from manufacture. These interactions can affect the mechanical, physical and chemical properties and consequently also the behaviour of the material of interest.

A pharmaceutical compound (10 mg/mL) was dissolved at pH 4 and at pH 10, then both samples were simultaneously heated in a MC-DSC. Thermal activity was evident, indicative of chemical reactions occurring in the samples. Under basic conditions the reaction was endothermic, while in acidic conditions the reaction was exothermic. When the logarithm of the thermal activity was plotted versus the reciprocal temperature, it became apparent that there were at least two reaction pathways with different activation energies at pH 10, while at pH 4 there was only evidence of a single degradative reaction. This information would be very useful in designing traditional HPLC stability screening studies since under basic conditions, this compound should clearly be stressed at lower rather than higher temperatures.

Solvated systems can be studied by techniques such as moisture sorption, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and isothermal calorimetry. Although in theory any one of these techniques can provide adequate data on the energy changes associated with solvation or desolvation, in practice isothermal microcalorimetry often provides superior data on pseudo-polymorphs, especially when only small (milligram) samples are available, or when unexpected results are obtained from other thermal techniques. For example, TGA was unable to detect formation of a drug hydrate in the presence of lactose monohydrate since there was no net change in mass associated with exchange of water between the drug substance and the lactose excipient.

DSC是在定义的气氛下测量样品发生转变时的温度与热流随温度或时间变化的函数关系；MDSC是在传统DSC上的提高，它将总的热流分解成可逆热流(热容)和不可逆(动力学)组分。可逆的信号包括热容，例如玻璃化转变和熔化；不可逆热流信号包括动力学成分，如结晶、结晶的完整性和重结晶、以及固化和分解等。

因为药物晶体具有很好的储存稳定性，药物公司在新药物配方中倾向采用结晶化合物。然而经常碰到的问题是药物存在多种结晶形式，即通常所说得多晶型。由于多晶型的每种晶型的物理性质、比如分散速率和生物活性有很大的不同，因此控制结晶的形势和含量显得十分重要。

DSC是在定义的气氛下测量样品发生转变时的温度与热流随温度或时间变化的函数关系；MDSC是在传统DSC上的提高，它将总的热流分解成可逆热流(热容)和不可逆(动力学)组分。

The development of monoclonal antibody (Mab) based drugs has undergone considerable growth since the release of the first Mab in the mid-eighties. Intuitive biophysical tools that examine and quantify interactions and conformational dynamics are important in demonstrating and understanding local and global conformational changes. The structure of antibodies as well as other macromolecules is related to its function and efficacy therefore control over these parameters is essential. The association of antigens to antibodies or of antibodies to delivery assemblies such as liposomes or gold nanoparticles can be addressed by isothermal titration calorimetry (ITC) while the folding of antibodies can be assayed using differential scanning calorimetry (DSC). Both techniques offer the advantage of using native solutions and both instruments are offered by TA Instruments.

The amount of moisture in pharmaceutical formulations is an important quality control parameter because it can affect their long-term stability and ultimate effectiveness as well as short-term processability. Techniques such as Karl Fischer titration, moisture evolution analysis (1,2), and thermogravimetric analysis (TGA) have been used for determining pharmaceutical moisture levels. However, these techniques often have trouble differentiating between “free” surface water (the source of problems) and bound water present in the chemical formulation.