چکیده (انگلیسی):

Accurate, sensitive and precise methods have been developed for determination of aspirin,
caffeine, and paracetamol, in their ternary mixture with minimum sample pretreatment and
without previous separation.
Method (A) is a spectrophotometric one that depends on determination of aspirin and paracetamol
using the successive derivative of the ratio spectra and measuring the amplitudes at 241.2 and
228.2 nm, respectively. Caffeine is indirectly determined using a calculated equation by measuring
the amplitude of the third derivative spectra at 285.6 at which there is no interference from paracetamol
and interference from aspirin was removed by subtraction as aspirin was selectively determined
at 241.2 nm, where CAF showed no absorbance.
Method (B) depends on quantitative TLC-Densitometric separation of the ternary mixture using
silica gel 60 F254 plates and scanning at 230 nm using chloroform:methanol:acetic acid:ammonia
solution (95:5:0.5:0.2, by volume) as a developing system.
The proposed methods have been validated as per ICH guidelines and USP requirements. Moreover
the developed methods have been applied for determination of the above mentioned drugs in different pharmaceutical formulations where no interference from the excipients has been detected.
Statistical comparison of the results obtained from the suggested methods with those of the
reported HPLC method showed no significant difference. The developed methods can be considered
sensitive, accurate, and cost-effective methods.