Chromatographic methods for the separation and determination of paracetamol and tramadol

ABSTRACT

Two chromatographic methods have been developed for the separation and determination of paracetamol [P] and tramadol [T]. The methods are applicable for the determination of both drugs either separately or in mixture. The first method is TLC scanning method in which the two drugs were separated on silica gel plate using methanol water glacial acetic acid 50 50 25 v/v as a developing system and spots were detected by UV scanning at 250nm for paracetamol and 275nm in case of tramadol. The calibration curve was found linear from 3 to 15 micro g/spot and from 14 to 80 micro g/spot in case of paracetamol and tramadol, respectively. The method was applied for the determination of both drugs in pure form with mean percent recoveries of 100.34 +/- l. 124 and 100.59 +/- 1.104 for paracetamol and tramadol, respectively. The method was successfully applied for the determination of both drugs in laboratory prepared mixture. The second method is an HPLC method in which the two drugs were separated on Hypersil MOS CIS [200x4.6mm] column using a mixture of 0.5M solution of potassium dihydrogen phosphate pH 3.3 and methanol 3565 as a mobile phase. Detection was carried out by ultraviolet detection at 280nm. Linear relationship between the peak areas and concentrations were given over a range of 10-360 micro g/ml and from 20 to 360 micro g/ml for paracetamol and tramadol, respectively. The HPLC method was applied for the determination of both drugs in pure form with mean percent recoveries of 100.43 +/- 0.84 and 100.19 +/- 0.78 for paracetamol and tramadol, respectively. The method was successfully applied to the determination of both drugs in laboratory prepared mixture. The validity of TLC method and HPLC method was assessed applying the standard addition technique for the determination of paracetamol and tramadol in acetamadol tablets. Statistical comparison between the reference methods and the proposed methods showed no significant difference