Tamboli et al Journal of Drug Delivery & Therapeutics. 2022; 12(4-S):210-213 ISSN: 2250-1177 [210] CODEN (USA): JDDTAO Available online on 15.08.2022 at http://jddtonline.info Journal of Drug Delivery and Therapeutics Open Access to Pharmaceutical and Medical Research Copyright © 2011-2022 The Author(s): This is an open-access article distributed under the terms of the CC BY-NC 4.0 which permits unrestricted use, distribution, and reproduction in any medium for non-commercial use provided the original author and source are credited Open Access Full Text Article Review Article Clinical Trials: Essential Stage in Development of Drug Tamboli S.S., Surwade A.B., Mahale K.J., Khairnar K.B., Avhad K.B., Avhad A.V., Chavan A.G., Kaluse P.S., Darekar A.B.* , Ugale P.G*, Jadhav S.S.* Krantiveer Vasantrao Narayanrao Naik Shikshan Prasarak Sanstha, Institute of Pharmaceutical Education and Research-422002 Article Info: _____________________________________________ Article History: Received 20 June 2022 Reviewed 28 July 2022 Accepted 09 August 2022 Published 15 August 2022 _____________________________________________ Cite this article as: Tamboli SS, Surwade AB, Mahale KJ, Khairnar KB, Avhad KB, Avhad AV, Chavan AG, Kaluse PS, Darekar AB, Ugale PG, Jadhav SS, Clinical Trials: Essential Stage in Development of Drug, Journal of Drug Delivery and Therapeutics. 2022; 12(4- S):210-213 DOI: http://dx.doi.org/10.22270/jddt.v12i4-s.5621 Abstract ___________________________________________________________________________________________________________________ This article gives an idea about the clinical trials and way its importance in the development of the vaccine. The different phases which are involved in clinical trials like phase I, phase II, phase III, and phase IV. Each phase role in the development of vaccines and how clinical trials play an important role in the treatment of various diseases. The role of a clinical trial is to help society and the entire medical community by contributing to the research and development of new drugs concerning their safety and efficacy. Keywords: Preclinical trials, phase I trial, phase II trial, phase III trial, phase IV trial *Address for Correspondence: Darekar A.B., Ugale P.G., Jadhav S.S., Krantiveer Vasantrao Narayanrao Naik Shikshan Prasarak Sanstha, Institute of Pharmaceutical Education and Research-422002 INTRODUCTION: The clinical trial is an inseparable subject between the pharmaceutical industries and human health. It is the type of clinical study or research study that tests the effectiveness, and toxicity of the new drug. For any new drug to enter a clinical trial it must pass preclinical studies. In studies all about that chemical entity on human being like toxicity, effectiveness, pharmacokinetics, and pharmacodynamics information. Clinical research is a branch of health care science that determines the safety and effectiveness (efficiency) of medication, diagnostic products, and treatment intended for human use. 1 There are two main types of clinical studies: 1) Clinical trial (interventional studies). 2) Observational studies. The first recorded clinical trial in the year 1747 by Scottish James Lind on scurvy disease now known as vitamin C deficiency. James Lind is known as the father of clinical trials. Then later first published a randomized control trial in 1948 on streptomycin treatment of pulmonary tuberculosis in MRS (medical Research council investigation). 2,3 Advantages of clinical trails: 1) Help to identify new vaccines in the treatment of various diseases 2) Help to study and learn more about the disease 3) Help to understand body action in response to the drug. 4) Help to improve pharmacological knowledge and help in the effective treatment of disease 5) Helps society and the entire medical community by contributing to research. Disadvantages of clinical trials: 1) It is possible that the new treatment may not be better than the current treatment of the disease and may cause several side effects. 2) Some patients may give a placebo effect instead of the active new drug. 3) Patients have to frequently visit the hospital for treatment, regular dose, stay, etc. 4) Chances to cause several adverse effects. 4,5 Phases of a clinical trial: 1) Preclinical studies-Preclinical studies are performed in vitro (test tube or cell culture) & In vivo (Animal) experiments. It is also possible to execute in silico profiling using computer models of the drug-target interaction. There are several types to perform clinical trials. Those are the following; 1) Screening test- It is an easy and fast-performing test. That will be shown the presence or absence of pharmacodynamic activity. example-hypoglycemic activity.