Three nanocomplexes of Zn(Ⅱ), Mn(Ⅱ), Fe(Ⅱ) with theophylline were synthesized by ultrasonic sonication method. Melting point, molar conductivity, solubility, flame atomic absorption, Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-vis) spectroscopy and C/H/N elemental analyses were used to investigate and suggest the structure of the nanocomplexes. Size and morphology of the nanocomplexes were measurement by transmission electron microscopy (TEM), ranging from 6-22 nm. Efficacy of the nanocomplexes synthesized was examined against four types of bacterial strains: Staphylococcus aureus, Bacillus subtilis (Gram-positive bacteria), Klebsiella pneumonia and Escherichia coli (Gram-negative bacteria). The results showed that all nanocomplexes had very high susceptibility to inhibit bacterial growth, as indicated by their inhibition zones between 98% and 100%.

Three nanocomplexes of Cu(Ⅱ), Co(Ⅱ), and Ni(Ⅱ) with theophylline were synthesized by ultrasonic sonication method. This method was used to produce smaller and narrow-distributed nanoparticles without any aggregations. Melting point, molar conductivity, solubility, flame atomic absorption, Fourier-transform infrared spectroscopy (FTIR) and elemental analysis (C, H, N, and S) were used to identify and to suggest the structure of the synthesized nanocomplexes. The transmission electron microscopy (TEM) results exhibited that the size of nanocomplexes was in the range of 15-25 nm. The efficacy of the synthesized nanocomplexes was examined against four types of bacterial strains, Staphylococcus aureus, Bacillus subtilis (gram-positive bacteria), and Klebsiella pneumoniae, Escherichia Coli (gram-negative bacteria). The results showed that all nanocomplexes had very high susceptibility to inhibit bacterial growth, as they resulted in an inhibition zone between 98% and 100%. The copper nanocomplex gave the highest inhibition zone by 100% for each type of bacterial strains, due to the surface plasmon. Therefore, a further test for the copper nanocomplex Cu(THP)₂(H₂O)₂(Cl)₂ was carried out on skin injuries of laboratory mice after it was converted into cream with vaseline and was found to have a very potent influence in healing skin injuries.