Figure 3

Differential scanning calorimetry (DSC) thermograms (A–C) and FTIR spectra (D–F) of metformin hydrochloride (MET) complexes. Complexes prepared using Carbopol (CB), sodium dodecyl sulfate (SDS), and tannic acid (TA) prepared at different charge ratios. Spectra are compared to that of free MET and ligands (CMC; critical micelle concentration, Mixture; the physical mixture of MET and ligand at 1:1 charge ratio).