Comparative Quantitative Analysis of Cetirizine Dihydrochloride by HPLC (High Performance Liquid Chromatography) and q_NMR (Quantitative Nuclear Magnetic Resonance) Techniques

In the pharmaceutical industry, the primary method of analysis comes from High-Performance Liquid Chromatography (HPLC) and Gas chromatography (GC). Although these methods are excellent in their ability to quantitate data there exists another option that isn’t readily used in quantitative analysis. Quantitative Nuclear Magnetic Resonance (qNMR) exists as another viable alternative, unlike HPLC and GC techniques qNMR does not require any specific chromatographic conditions or the constant generation of mobile phase waste. This work looks to develop, optimize and compare quantitative methods of analysis for Cetirizine Dihydrochloride by HPLC and qNMR. HPLC methods of analysis adhere to a Design of Experiment1,2 approach which employs a screening stage followed by a later optimization stage. A Plackett-Burman design assessed the potential critical analytical attributes (CAA) (Buffer Concentration, Buffer pH, Organic % and Injection volume) by evaluating the responses (Capacity Factor, Plate Count, Tailing Factor and Retention Time). A Box Behnken design further optimized results by evaluating main interactions and their quadratic effects. Optimization results show optimal chromatographic conditions occurring with a 2.1 pH 40 mM phosphate buffer with Acetonitrile 22:78 v/v as a mobile phase at a flow rate of 2 mL/min and an injection volume of 5 uL. Optimal conditions showed a 4% deviation in retention time from the predicted DOE value. Validation of the HPLC method based on the guidelines outlined by ICH Q2R13 showed a high degree of linearity (r square value of 0.9994), accuracy, precision, and stability. In a D2O based solvent system using maleic acid as an internal standard, the q-NMR analysis looks at the peak area of three sets of protons in cetirizine with respect to the olefinic protons peak area of maleic acid. When plotted over a concentration range of 20 -100mM linearity from all three cetirizine peaks show r square values greater than 0.998. Triplicate runs of each calibration sample show the highest %CV being 0.483, which indicates excellent precision. NMR waste generation is relatively small in comparison to the HPLC method, compared to the 1.5 L acetonitrile used in HPLC qNMR analysis only required 25 mL of deuterated water. Method development was also drastically shorter at roughly 2 hours when compared to the 15 hours allocated to the HPLC method. The results of this study show that not only is qNMR up to the task of quantitative analysis but is capable of doing so while significantly decreasing the generation of waste and time of analysis