TITLE: 
                        
                            In Situ Characterization of Lopinavir by ATR-FTIR Biospectroscopy
                                
                                
                                    AUTHORS: 
                                            Alireza Heidari 
                                                    
                                                        KEYWORDS: 
                        ATR-FTIR Biospectroscopy, Simulation, Lopinavir, Breakdown, Coronavirus Disease-2019, COVID-19, Infection, Protective and Therapeutic Effect, Potent Drug 
                                                    
                                                    
                                                        JOURNAL NAME: 
                        Computational Chemistry,  
                        Vol.8 No.3, 
                        July
                                                        14,
                        2020
                                                    
                                                    
                                                        ABSTRACT: 
	Lopinavir is an antiretroviral of the protease inhibitor class (Figure 1 and Figure 2). It is used against HIV infections as a fixed-dose combination with another protease inhibitor, ritonavir (lopinavir/ritonavir). In the current research, the stimulated ATR-FTIR biospectroscopy of liquid sample of Lopinavir was investigated. The stimulated ATR-FTIR diffractions emitted through focusing the second harmonic laser beam Nd:YAG into the sample were recorded by Echelle spectrometer and ICCD detector. Increasing the energy of laser beam from 2.6 (mJ) to 16 (mJ) led to increase in stimulated ATR-FTIR signal but after breakdown threshold of liquid sample, further increasing energy led to the decrease in stimulating ATR-FTIR signals and for energies higher than 20 (mJ), they were disappeared.