819METHOD DEVELOPMENT AND VALIDATION OF LAMIVUDINE AND EFAVIRENZ IN HUMAN PLASMA BY LC-MS/MSComparative bioavailability studies permit judgement as to the bioequivalence of Drugs. The determination may in turn lead to important decision related to Drug product selection by pharmacists. However it should be noted that neither bioavailability nor bioequivalence data could be generated without analytical methodology to accurate measure Drug in biological fluids. The developed and validated bioanalytical method for Lamivudine and Efavirenz drugs shows satisfactory linearity, precision, accuracy and stability. The method can be particular useful for pharmacokinetics and pharmacodynamicsbala.hospira@gmail.comResearch6122015Method development,Validation,Bioanalytical,Lamivudine,EfavirenzBalammal G,Maya Sharma,Saravana Kumar AResearch Scholar, Pacific Academy of Higher Education and Research University, Pacific Hills, Udaipur – 313024, Rajasthan, India.,Research Scholar, Pacific Academy of Higher Education and Research University, Pacific Hills, Udaipur – 313024, Rajasthan, India.,Sri Venkateswara College of Pharmacy, Chittoor, Andhra Pradesh – 517 127, India.