Sharma et al. European Journal of Pharmaceutical and Medical Research www.ejpmr.com │ Vol 8, Issue 9, 2021. │ ISO 9001:2015 Certified Journal │ 282 REVIEW ON VARIOUS PHARMACEUTICAL APPLICATIONS OF ULTRAVIOLET SPECTROSCOPY Dr. Abhishek Soni, Dr. Amit Chaudhary, Priyankul Palia and Gaurav Kumar Sharma* School of Pharmacy Abhilashi University, Mandi (HP). Article Received on 06/07/2021 Article Revised on 26/07/2021 Article Accepted on 16/08/2021 INTRODUCTION In everyday practise, analysts must analyse multicomponent formulations, biotherapeutic medicines, and complicated matrix materials quickly. For these purposes, a variety of ultraviolet (UV) spectrophotometric approaches are used. Among all of these techniques, UV spectrophotometry is the most popular. The absorption of visible and UV radiation (200–400 nm) is connected with the excitation of electrons in both atoms and molecules from lower to higher energy levels, according to the basic concept of UV spectroscopy. Because matter's energy levels are quantized, only light with precisely the right quantity of energy may drive transitions from one level to the next. [1] UV spectrophotometric approaches supported the principles of additivity and absorbance, which involve recording and mathematically processing the absorption spectra of normal and sample solutions within the same or other ways. Types Of UV Spectroscopic Analytical Techniques The many UV spectroscopic analysis procedures are as follows: Simultaneous equation method, difference spectrophotometry, derivative spectrophotometry, absorbance ratio spectra, derivative ratio spectra, successive ratio - derivative spectra, Q-absorbance ratio method, absorptivity factor method, dual wavelength method, absorption factor method, multivariate chemometric methods, and isosbest are some of the absorption factor methods. Simultaneous Equation Method Simultaneous equation method is useful to determine drugs which absorb at the λ max of other in the binary or ternary mixture. Consider The absorptivities of X at λ 1 and λ 2 , ax 1 and ax 2 , respectively. The absorptivities of Y at λ 1 and λ 2 , ay 1 and ay 2 , respectively. The absorbance of the dilute sample at λ 1 and λ 2 , A 1 and A 2 , respectively X, have concentration c x and Y have concentration c y in dilute sample. According to the fact, the concentration of mixture is the sum of the individual concentrations of X and Y. So, at λ 1 A 1 = ax 1 bcx +ay 1 bcy ….. (1) At λ 2 A 2 = ax 2 bcx +ay 2 bcy …… (2) If cell is 1 cm, b = 1 equation 2 become, c y = (A- ax2cx)/ay2 Substituting value of cy in equation (1), thus ax 1 bcx = A- ay 1 cy c x =(A 2 ay 1 -A 1 ay 2 )/(ax 2 ay 1 -ax 1 ay 2 ) ……… (3) S imilarly for cy c y = (A 1 ax 2 -A 2 ax 1 )/(ax 2 ay 1 -ax 1 ay 2 ) …… (4) “Glenn” have been suggested criteria for obtaining maximum precision, based on absorbance ratio that place limit on the relative concentration of the component of the mixture. The criteria for that ratio should lie outside SJIF Impact Factor 6.222 Review Article ISSN 2394-3211 EJPMR EUROPEAN JOURNAL OF PHARMACEUTICAL AND MEDICAL RESEARCH www.ejpmr.com ejpmr, 2021,8(9), 282-289 ABSTRACT Due to the growing amount of multicomponent formulations, biotherapeutic medicines, and complicated matrix samples in queue, quick and simple analytical methods are required. For these purposes, a variety of ultraviolet (UV) spectrophotometric approaches are used. On the basis of the principle of additivity, absorbance difference, and processing absorption spectra, many UV spectrometric methods have been created. This review will cover simultaneous equation method, difference spectrophotometry, derivative spectrophotometry, absorbance ratio spectra, derivative ratio spectra, successive ratio - derivative spectra, Q-absorbance ratio method, absorptivity factor method, dual wavelength method, absorption factor method, multivariate chemometric methods, and isosbestic point method. KEYWORDS: Ultraviolet spectroscopy, Simultaneous equation method, Derivative spectrophotometry, Derivative ratio spectra, Isosbestic point method, Multivariate chemometric methods. *Corresponding Author: Gaurav Kumar Sharma School of Pharmacy Abhilashi University, Mandi (HP).