Assessment of quality of paracetamol and ranitidine drugs by spectroscopic studies
Sharmin Shahjahan, Fouzia Ahmed Anny, Mohammad Shoeb, Md. Mizanur Rhaman, Md. Mazharul Islam, Md. Iqbal Rouf Mamun

Four tablet samples containing 500 mg of paracetamol and five tablet samples containing 150 mg of ranitidine were collected from local pharmacies of Dhaka city to evaluate the quality by physical, Fourier transform infrared (FT-IR), Ultraviolet-visible (UV-Visible) and 1H & 13C nuclear magnetic resonance (NMR) spectroscopic studies. Weight variations of paracetamol and ranitidine tablets were 0.11-3.09% and 0.97-1.02%, respectively, which are in the allowed variation of 5%. The pH, average moisture and average ash content of paracetamol tablets were 6.45-6.95, 0.62±0.03-2.28±0.93% and 0.01±0.01-1.12±0.02%, respectively and ranitidine tablets were 5.46- 5.55, 10.07±2.47-17.58±5.32% and 1.14±0.25-3.95±0.28%, respectively. The prominent IR absorption bands of standard paracetamol were 3350, 3150, 2924, 1656, 1563, 1441, 1013 and 715 cm-1 for the presence of N-H, O-H, C-H, C=O, C=C (two absorbance bands), C-O and =C-H functional groups, respectively and standard ranitidine were 3257, 1620, 1381, 1191, 951, 759 and 697 cm-1 for the presence of secondary N-H-furan overlap, C=C-NO, N-O, C-N, C-S, aromatic (CH) and sp3 (C-H) groups, respectively. The λmax of standard paracetamol and ranitidine were 294 and 332 nm in the UV spectrum, respectively. 1H and 13C NMR spectral data of the standard paracetamol, ranitidine and samples were identical.

Keywords: Paracetamol, Ranitidine, Physicochemical properties, FT-IR, UV-visible, 1H NMR, 
13C NMR.