Low dose aspirin estimation: an application to a human pharmacokinetic study.

Low dose to very high dose aspirin is used to prevent heart attack. We have developed and validated a sensitive and robust method that could detect low levels of aspirin and salicylic acid in plasma and also a novel sample collection procedure to carry out sample preparation at room temperature. The total run time was 3.00 min; the developed method was validated in human plasma with a lower limit of quantitation of 0.99 ng/mL for aspirin and 2.01 ng/mL for salicylic acid. A linear response function was established for the range of concentrations 0.99-756.20 ng/mL (r > 0.998) for aspirin and 2.01-2486.86 ng/mL for salicylic acid. The intra- and inter-day precision values for aspirin and salicylic acid met the acceptance as per FDA guidelines. The developed assay method was applied to an oral pharmacokinetic study in humans.