A simple and rapid ultra-high-performance liquid chromatography (UHPLC) method using UV detection was developed for the simultaneous determination of eight β-lactam antibiotics in human plasma including four penicillins amoxicillin (AMX) cloxacillin (CLX) oxacillin (OXA) and piperacillin (PIP) and four cephalosporins cefazolin (CFZ) cefepime (FEP) cefotaxime (CTX) and ceftazidime (CAZ). in gradient elution mode at a flow rate of 500 μl/min. Detection was performed at 230 nm for AMX CLX OXA and PIP and 260 nm for CFZ FEP CTX and CAZ. The total analysis time did not AT-406 exceed 13 min. The method was found to be linear at concentrations ranging from 2 to 100 mg/liter for each compound and all validation parameters fulfilled international requirements. Between- and within-run accuracy errors ranged from ?5.2% to 11.4% and precision was lower than 14.2%. This simple method requires small-volume samples and can easily be implemented in most clinical laboratories to promote the therapeutic drug monitoring of β-lactam antibiotics. The simultaneous determination of several antibiotics considerably reduces the time to results for clinicians which may improve treatment efficiency especially in critically ill patients. INTRODUCTION Penicillins and cephalosporins form two classes of β-lactam antibiotics. They are extensively prescribed for the treatment of potentially life-threatening infections including peritonitis respiratory tract infections endocarditis meningitis and skin and soft tissue infections which involve a wide range of bacteria (1). The pharmacokinetic-pharmacodynamic (PK-PD) study of these antibiotics has consistently shown that their antibacterial activity is time dependent; i.e. the time that the plasma concentration remains above the MIC between two administered doses is well correlated with treatment efficiency. According to many authors the optimal bactericidal activity in critically ill patients is achieved when plasma concentrations are AT-406 above the MIC or even greater than 4 to 5 times the MIC for 70% to 100% of AT-406 the dosing interval (2 -10). The failure of antibiotic treatment and the development of resistant strains of bacteria may occur in patients with insufficient antibiotic exposure. Conversely concentrations of β-lactam antibiotics that are too high may induce uncommon but severe adverse reactions mainly neurotoxicity symptoms including seizures and encephalopathy (11 12 Therapeutic drug monitoring (TDM) of β-lactam antibiotics is therefore clinically relevant to ensure optimal antibiotic exposure thus improving treatment NR4A3 efficiency while minimizing toxicity and reducing the emergence of resistance. TDM AT-406 of β-lactam antibiotics is specifically useful in critically ill patients in whom the pharmacokinetics of drugs are altered and variable. Such patients frequently have associated hypoalbuminemia and/or an inflammatory syndrome resulting in a large increase in the volume of distribution. Some patients may develop organ dysfunction resulting in antibiotic drug accumulation whereas other patients with septic shock may exhibit hyperdynamic circulation leading to increased renal eradication (13 14 Many analytical options for the dedication AT-406 of β-lactam antibiotics in the plasma/serum of individuals have already been reported (for evaluations see the function of El-Shaboury et al. [15] and Carlier et al. [16]). Several methods were created using regular high-performance liquid chromatography (HPLC) with UV recognition and have problems with a long evaluation period (17 -21). Additional methods produced by using ultra-high-performance liquid chromatography (UHPLC) in conjunction with mass spectrometry recognition allow shorter evaluation times but need materials that aren’t readily available generally in most laboratories (22 -27). In medical practice there’s a critical have to develop an easy-to-implement technique that could cover an array of β-lactam antibiotics therefore reducing enough time to outcomes for clinicians. Such a way would promote and enhance the efficiency of antibiotic TDM undoubtedly. Compared to that end the simultaneous dedication of main β-lactam antibiotics in one operate using UHPLC with UV recognition (UHPLC-UV) could be a bargain and hasn’t been reported up to now. Specific analytical advancements are therefore necessary to propose a way with basic and rapid test preparation adequate parting of the examined compounds and an adequate recognition sensitivity that could meet up with the clinician requirements for TDM. The purpose of AT-406 this scholarly study was to.