1,1-Dimethylbiguanide hydrochloride

In vitro biocidal activities results of both metformin hydrochloride free ligand and their metal complexes clearly show that the compounds have both antibacterial and antifungal potency against the tested organisms (Table 9, and illustrated in Fig. 7). By comparison between the biological evaluation of metformin HCl complexes with the standards Tetracycline as (antibacterial agent) and amphotericin B as (antifungal agent), the results items of highest-to-lowest effective can be summarized as follows.

The infrared absorption bands are one of the important tools of analyses used for determining the mode of chelations. The most significant bands (Fig. 2) of Metformin HCl ligand can be classified into three groups: (1) NH vibrations of primary (–NH₂), secondary (–NH) and imino (–C=NH) groups; (2) C–N and C=N vibrational bands, and (3) C–H vibrations of the methyl groups. According to the three fundamental vibrational groups mentioned above, the Metformin HCl free ligand can be interpreted as follows: N–H vibrations: the N–H stretching of C=N–H group occurs in the region of 3400–3100 cm_-1.

Metformin HCl (MTF), a biguanide, was discovered in 1920s and since then it is one of the first-line drugs used alone or in combination with other hypoglycemic agents for the management of NIDDM (Setter et al. 2003). The drug in monotherapy is used, as an adjunct to diet to lower blood glucose in patients whose hyperglycemia cannot be managed on diet alone (Hawkins et al. 2002). MTF primarily acts by reducing endogenous glucose production due to which it is popular despite its high incidence of gastrointestinal intolerance (Dang et al. 2007).