Original Article RAPID ASSAY DEVELOPMENT OF DICLOFENAC SODIUM COATED TABLET ASSAY USING FTIR COMPARED TO HPLC METHOD ILMA NUGRAHANI 1 , NOVENSIUS DILLEN 1 1 School of Pharmacy, Bandung Institute of Technology, Indonesia Email: ilma_nugrahani@fa.itb.ac.id Received: 06 Mar 2018, Revised and Accepted: 13 Apr 2018 ABSTRACT Objective: A lot of coated tablet preparations of diclofenac have been marketed. This research aimed to develop and validate a quantitative analysis method for diclofenac sodium coated tablet using Fourier Transform Infrared (FTIR), which never reported. Methods: The quantification was done by measuring the sample spectra, which then was converted into its derivative. Areas under the curve (AUC) of the derivative spectrums were plotted against the concentrations; corresponding to the calibration graphic. Then, the validation method was carried out by evaluating the accuracy, precision, linearity, range, limit of detection (LOD), and limit of quantification (LOQ). Results: The results showed that diclofenac sodium had a specific peak within the wavenumber range of 1550-1605 cm -1 . This area showed linearity to concentration within the range 0.1-1.0% w/w, with coefficient correlation of 0.9998. Recovery was found within 98-102% w/w. The intra and inter-day precision showed a coefficient of variance below 2%. The LOD and LOQ were 0.0127% and 0.0424% respectively. Further, a comparative study was performed, between this method and the compendia method using HPLC. The results showed that the measurement method using FTIR has an advantage in terms of time and cost. Conclusion: Based on all data, it is concluded that FTIR can be used as a valid alternative method. It is faster and more cost-effective for diclofenac sodium coated tablet content determination, compared to the compendia method. Keywords: Assay, Comparative study, Diclofenac sodium, FTIR, HPLC © 2018 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) DOI: http://dx.doi.org/10.22159/ijap.2018v10i4.25682 INTRODUCTION Methods for active compound analysis have developed rapidly, especially since the invention of various analytical instruments such as HPLC and gas chromatography. The development of quantitative analysis is driven by the need of more rapid, accurate and simple method of analysis. On the other side, the efficiency of cost should be considered; beside the realized of green pharmacy which is strong issued and recommended to be supported [1-3]. One of the developing methods prospectively is the determination level of an active substance by using FTIR instrument due to its free solvent usage. FTIR method has been developed and reported as a method of quantitative analysis for some active substances [4-7]. This method was explained to offer some advantages, such as simple sample preparation and minimum usage of organic solvents. Diclofenac sodium is a nonsteroidal anti-inflammation drug (NSAID) with a mechanism of action inhibiting the cyclooxygenase enzyme, causing decreasing of prostaglandin synthesis [8, 9]. For some purposes, the diclofenac tablets are formulated in the coated form, such as for extended release or protect from degradation [10-15]. Film coating of tablets and other solid dosage also formulated to mask the unpleasant taste and odours. Furthermore, coated tablet is produced to improve the appearance of dosage forms; for ease of swallowing; to achieve colonic drug delivery and controlled drug delivery, among others. Many excipient are added to be the coating materials for pharmaceutical products [10-15]. Assay method for diclofenac sodium coated tablet preparation in the compendia is by using HPLC [8, 9, 16]. Some developments also have been reported to improve the performance [17-19]. One of the difficulties in the coated-dosage form analysis is the matrix's separation. In the common analysis, the matrices are extraction by appropriate solvents, if needed also supported by other steps of chromatography. In some practical cases, the coating excipient is not separated. It will increase the viscosity of the analyte solution. Then, that causes troubles of the instrument. Besides, prolongs the time consumption. Another method which has reported to quantify diclofenac is spectro-photometry UV/visible [20, 21], and voltammetry-GC [22]. However these methods also need solvent for extraction In this study, FTIR instrument was proposed as a quantitative method for coated tablet of diclofenac sodium directly without extraction. Diclofenac sodium formula is C14H10Cl2NNaO2 with molecular weight of 318.129 g/mol. Diclofenac sodium structure as shown in fig. 1 has amine bond (N-H), carbonyl bond (C = O), and carbon double bond (C = C) which showing strong peaks in the IR spectrum [8, 9, 16, 23-25]. These bonds are predicted to have a correlation with the quantity of the measured substance so that it is potentially used to determine diclofenac sodium content in a sample. Fig. 1: Diclofenac sodium chemical structure The purpose of this study was to develop a more rapid and simple assay method for diclofenac sodium in the coated tablet using FTIR directly. It means, without extraction and separation physically. Furthermore, the parameters of validation resulted would be compared with the trial obtained by method from the compendia, completely with a short cost analysis. MATERIALS AND METHODS Material The materials used in this study were: standard of diclofenac sodium (PT Pharos), KBr crystals (IR-spectra grade), acetone (Brataco, Indonesia), aqua-bidestilata, methanol pro HPLC, phosphate buffer pH 2.5, tablet matrix base, micropore 0.45 μm filter paper, and diclofenac sodium coated tablet preparations as samples. International Journal of Applied Pharmaceutics ISSN- 0975-7058 Vol 10, Issue 4, 2018