New ecological method for determination of different β-lactams: application to real human plasma samples

Recently, the use of antibiotics has become widespread all over the world resulting in bacterial resistance to these antibiotics, which requires alternative medications or higher doses of antibiotics. Implementation of an easy analytical method that can analyze a wide range of β-lactam antibiotics in a single run is important to reduce the time of therapeutic drug monitoring (TDM) in hospitals and minimize the spreading of bacterial resistance. A novel environmentally harmless HPTLC method was developed and validated following FDA recommendations for analysis of four β-lactams; cefaclor, cefotaxime, cefepime, and meropenem, in human plasma. A solvent mixture of ethylacetate : methanol : deionized water : formic acid (60 : 30 : 15 : 1, by volume) was the used developing system, detection was carried out at 270 nm, and valacyclovir was used as an internal standard. A lower limit of quantitation (LLOQ) was found to be 0.1 μg per band for all the analyzed drugs. Validation parameters were calculated and found to fulfil the international requirements for bio-analytical method validation. Additionally, each of the studied antibiotics was given to a group of healthy volunteers from which blood samples were collected at t(max) of each, methanol was used for precipitation of plasma protein, and the developed method was used for calculation of the concentrations in the separated plasma samples. The developed method, being a green one, and time and money saving, can be used for TDM of these drugs in clinical studies as well as for quality control analysis in pharmaceutical companies. The proposed method is the first developed HPTLC method for the simultaneous bio-analysis of the selected β-lactams.