Fig. 1 a

2D-TLC densitogram of a standard mixture of Salbutamol, Guaiafenesin, Guaiacol and Bromhexine, (Rf SAL: 0.07, Rf GUF: 0.29, Rf GUL: 0.76, and Rf BR: 0.92). b 2D-TLC densitogram of ventocough® syrup (with sugar) containing Salbutamol, Guaiafenesin, Bromhexine, and excipients, (Rf SAL: 0.07, Rf Excipients: 0.21, Rf GUL: 0.76, and Rf BR: 0.92). c 2D-TLC densitogram of ventocough® syrup (without sugar) containing Salbutamol, Guaiafenesin, Bromhexine, and Excipients, (Rf SAL: 0.07, Rf Excipients: 0.21, Rf GUL: 0.76, and Rf BR: 0.92)