Solubilization of poorly soluble drugs: cyclodextrin-based formulations

The delivery of therapeutics preferentially to target tissue remains a considerable barrier to achieving effective clinical outcomes; this ultimately requires a molecule to display both optimal hydrophilic and lipophilic properties. cyclodextrins (CDs) are successfully applied as drug solubilizing agents and they are now routinely employed for this purpose in a range of pharmaceutical formulations. The literature boasts a range of methods for the formation of drug-CD complexes. The solvents and processing parameters used may vary, but the commonly used techniques can be broadly divided into spray drying, freeze drying, slurry method, kneading, solid phase complexation, co-precipitation, and neutralization. A variety of techniques have been employed to confirm the formation and utility of CD complexes, namely thermo-analytical methods, differential scanning calorimetry (DSC) or differential thermal analysis (DTA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM).