Bulletin of Trends in Chemical Sciences

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1 Bulletin of Trends in Chemical Sciences Paper Vol. 1 (2) (2016) Open access Quantitative estimation of aceclofenac and its pharmaceutical formulations using FTIR spectroscopy Nimmala Anvesh Reddy a, R. Lakshmipathy b, G. Venugopala Rao a, N.C. Sarada a * a Department of Chemistry, School of Advanced Sciences, VIT University, Vellore, Tamilnadu, India b Department of Chemistry, KCG College of Technology, Karapakkam, Chennai, Tamilnadu, India ABSTRACT The present study reports the environmental friendly Fourier Transform Infrared (FTIR) spectrometric method for the rapid and direct measurement of aceclofenac in pharmaceutical formulation. Sample preparation for measurements is simple and use of toxic solvents is totally eliminated. Simple Beer s law was applied in the FTIR region from 1785 to 1760 cm -1 for calibration development. A good calibration curve with linear regression of was obtained for the standards in the range of mg. The results of the study clearly reveal the capability of FTIR spectroscopy in direct determination of aceclofenac in pharmaceutical formulation and finished products. Keywords: FTIR; Aceclofenac; Calibration; Estimation; TQ Analyst; Introduction Aceclofenac, a phenyl acetic derivative related to diclofenac, is a widely used non steroidal antiinflammatory drug (NSAID). Aceclofenac contains not less than 99.0% and not more than the equivalent of percent of 2-[[2-[2-[(2, 6-dichlorophenyl) amino] phenyl] acetyl] oxy] acetic acid. [1]. It is a white or almost white crystalline powder. It is used in various pain conditions like rheumatoid arthritis, osteoarthritis and ankylosing spondylatis [2]. The molecular weight of aceclofenac is ; CAS no [3]. Chemical structure is shown in Fig.1. Literature survey reveals that various analytical methods are developed for determination of aceclofenac from pharmaceutical formulations such as titrimetric [4], stripping voltammetric [5], spectrophotometric and spectroflourimetric [6], and high performance liquid chromatography (HPLC) [7,8] methods. Fig.1 Chemical structure of aceclofenac Although HPLC was found to be precious tool for determination of drugs from pharmaceutical formulations, the time consumption, sample preparation and use of toxic solvents are the drawbacks of the technique. Use of spectrometric methods can be rapid and cost effective for analysis of finished pharmaceutical products. In last few years, FTIR spectroscopy has achieved much recognition as rapid analytical technique in the laboratories of pharmaceutical industries for qualitative analysis of raw and finished products [9].

2 Anvesh et. al/ Bulletin of Trends in Chemical Sciences 1 (2) (2016) Recent development of sophisticated software has constructed FTIR spectroscopy as a rapid and straightforward technique for quantitative determination of drugs from its pharmaceutical formulations. Therefore the present study was undertaken to develop a rapid, cheap, accurate and eco-friendly analytical technique for routine determination of aceclofenac from tablet formulations without use of any toxic solvents. Materials and methods Reagents and samples Analytical grade aceclofenac standard used for calibration in the present study was obtained from Sigma Aldrich Ltd. Commercially available tablets containing aceclofenac as an active ingredient were purchased from local medical stores. Sample pellets for FTIR analysis was prepared using IR spectroscopic grade KBr purchased from Merck Ltd. FT-IR spectral measurements Thermo Nicolet Avatar 330 FTIR spectrometer equipped with KBr optics and deuterated triglycine sulfate (DTGS) detector was used for acquisition of infrared spectra of standards as well as samples in the tablet form. The instrument was controlled by commercially available IR spectra analysis software package EZ-OMNIC (Thermo Nicolet Analytical Instruments). Atmospheric suppression for FTIR spectrum of each standard and sample was done by fresh background spectrum recorded from KBr pellet. All spectra were recorded in the Mid IR region from cm -1 averaging 32 scans at a spectral resolution of 4cm -1 at 25 C ±2 temperature. FT-IR Calibrations FTIR calibrations are performed as per the method proposed by Sherazi et al [10]. A set of 12 standards of aceclofenac containing the range between 0.01 and 1.0mg in KBr was prepared to formulate the 100mg pellets of total weight. Simple Beer s law model was developed for the quantitative determination of aceclofenac in tablet formulation by EZ-OMINC and TQ Analyst program (Thermo Electron Corporation, USA). In the TQ Analyst program aceclofenac standards ranging from 0.01 to 1.0mg were selected, that were already recorded. For best quantitative determination, specific carbonyl band i.e cm -1 was specified in the TQ Analyst program which is a better option to save the time and labor to measure peak height, peak width and peak area as compare to manual calculations. Area under band for all aceclofenac standards was calculated by the TQ Analyst software itself. Through cross validation, an excellent calibration curve was obtained between actual and predicted values of aceclofenac standards. Sample preparation The major advantage of FTIR technique is mere sample preparation procedure. The weighed tablet samples were fine powdered using a mortar and accurately weighed 1mg tablet samples was mixed with 99mg of oven dried KBr. A homogenous mixture of sample and KBr was obtained by grinding in mortar. Later the mixture was prepared into translucent 13mm disc by applying 6 tons of pressure for 5 min using KBr press provided with the FTIR spectrometer. The prepared translucent discs were recorded in the Mid IR range from cm -1 on Thermo Nicolet Avatar 330 FTIR spectrometer. Limit of detection and quantification The limit of detection (LOD), described as the minimum concentration from which it is possible to deduce the presence of the analyte with reasonable statistical certainty. To determine the limit of detection (LOD) and limit of quantification (LOQ) for the proposed method, the selected band area was measured at low concentration of standards, until the aceclofenac related signal disappeared. The analysis at the lowest amount which produced substantial peak was repeated for eleven times and calculated by the following formula [11] LOD = 3 x SD x Where SD is the standard deviation, C is the concentration of analyte and M is the mean band area. Similarly, LOQ was determined by the following equation. 17

3 Anvesh et. al/ Bulletin of Trends in Chemical Sciences 1 (2) (2016) LOQ = 10 x SD x Recovery efficiency The recovery efficiency was determined by the ratio of aceclofenac recovered (%) to the aceclofenac content (mg) added. The calculation was carried out by the following equation. R% = ( ) x 100 Where R is the aceclofenac recovered (%), A is added level of aceclofenac, B is the actual concentration of aceclofenac present in the sample and C is the concentration of aceclofenac after addition. Results and discussion Determination of the major component in drugs with FTIR spectrometry provides an enormous amount of spectroscopic information about the sample. FTIR now recognized as rapid analytical technique for both qualitative and quantitative analysis due to outstanding performances of recently developed software. The results of the present study accomplish the use of FTIR spectroscopy in rapid and simple measurements of quantity of desired active specie while performing quality control of pharmaceuticals. The FTIR spectrum of aceclofenac standards recorded in the mid IR region is shown in Fig.2. The FTIR spectrum shows number of peaks at different wave numbers which corresponds to different functional groups present in aceclofenac. Similarly, FTIR spectrum of tablets containing aceclofenac as active ingredient was also recorded (Fig.3a). The excipients commonly used for the solid commercial formulation are starch, magnesium stearate, manitol, sodium tripoly phosphate, avecil and talcum powder. The FTIR spectrum of mixed excipients is shown in Fig.3c. It is observed that the carbonyl band at cm -1 present in commercial tablet and aceclofenac standard is not observed in the FTIR spectrum of mixed exipients. The main idea of achieving rapid, direct and green method was fully achieved in the sense that strategy of avoiding extraction brought overcoming success as clearly shown in the spectra. The absence of significant interference band in mixed exipients has proven the method to be practical. The carbonyl band selected in FTIR region from cm -1 for quantification of aceclofenac standards (0.01 to 1.0mg) is shown in Fig.4. The availability of sophisticated software techniques has made the present work more rapid and simple. The FTIR spectrums recorded for standards were opened in TQ Analyst as it is able to generate the calibration in an easy and efficient way. For quantitative determination of aceclofenac in the pharmaceutical formulation a simple Beer s law model was employed based upon the measurement of carbonyl band area. A good calibration curve with excellent linear regression was obtained. The calibration curve with percentage difference plot between the actual and calculated values for the range of mg calibration standards obtained through TQ Analyst is presented in Fig. 5. A good calibration curve with linear regression of shows the tremendous sensitivity of FTIR spectroscopy for the determination of aceclofenac in pharmaceutical formulations. From calibration, the assessment of the errors was carried out by calculating the residual mean standard error of calibration (RMSEC) after comparing the actual concentration with the computed one for each component with the standard deviation of The root mean square error of prediction (RMSEP) was and the quantitative model also verified through root mean square error of cross validation (RMSECV) which was found to be The low error values obtained from the calibration shows the appropriateness to the present method for quantitative determination of aceclofenac by FTIR spectroscopy. The quantification of aceclofenac from tablets was carried using the regression equation obtained from the calibration of standards. The summary of the results obtained by the present method for aceclofenac is presented in Table.1. The concentration of aceclofenac determined was found to be in the range of % with labeled contents in analyzed tablet samples and are 18

4 Absorbance Anvesh et. al/ Bulletin of Trends in Chemical Sciences 1 (2) (2016) mg 0.05mg 0.1mg 0.2mg 0.3mg 0.4mg 0.5mg 0.6mg 0.7mg 0.8mg 0.9mg 1mg Wavenumbers (cm-1) Fig.2 FTIR spectra of aceclofenac standards in mid IR region Fig.3 FTIR spectra of a) aceclofenac in tablet formulations b) aceclofenac standard and c) Mixture of excipients 19 2

5 Absorbance Anvesh et. al/ Bulletin of Trends in Chemical Sciences 1 (2) (2016) mg 0.05mg 0.1mg 0.2mg 0.3mg 0.4mg 0.5mg 0.6mg 0.7mg 0.8mg 0.9mg Wavenumbers (cm-1) Fig.4 Response of the carbonyl band area to various concentrations of the aceclofenac standards by FTIR spectroscopy Fig. 5 TQ Analyst calibration of aceclofenac standards 20 3

6 Anvesh et. al/ Bulletin of Trends in Chemical Sciences 1 (2) (2016) are within permissible limits of pharmacopeia. The LOD and LOQ were calculated for this method was found to be 0.015mg g -1 and mg g -1 respectively for aceclofenac. Recovery test was used further for evaluation of the accuracy of the method. The statistical results obtained for the recovery test of aceclofenac for one of the selected sample is presented in Table.2 (Suppl. File). The high percentage recovery revealed that there is no any significant interference effect from any other excipients present in the formulation hence prove that this method is feasible for direct and rapid determination. Further the results obtained from the study were compared with other analytical techniques used in the quantification of aceclofenac from tablet formulations (Table-3 Suppl. file). The recovery % was found to be high and almost same compared to other analytical techniques. The recovery % from standard addition method was also high and between the prescribed standards [11]. These results confirm that the present proposed technique for the quantification of Aceclofenac using FTIR is prolific, rapid and cost effective in nature. Conclusion The present method for determination of aceclofenac in tablets using FTIR spectroscopy was found to be simple, rapid and eco-friendly technique. The high percentage recoveries of aceclofenac from pharmaceutical formulations show the feasibility of the present model. This results show that FTIR spectroscopy can be a potential analytical technique for qualitative and quantitative analysis of aceclofenac in pharmaceutical formulations. References [1] Zawilla, N.H., Mohammad, M.A.A., El Kousy, N.M., El- Moghazy S.M.: Determination of aceclofenac in bulk and pharmaceutical Formulations. J Pharma Biomed Anal. 27, (2002). [2] Brogden, R.N., Wiseman, L.R.: Aceclofenac: A review of its pharmacodynamic properties and therapeutic potential in the treatment of rheumatic disorders and in pain management. Drugs 52, (1996). [3] Ojha, A., Rathod, R., Padh, H.: Simultaneous HPLC UV determination of rhein and aceclofenac in human plasma J Chromatogra B. 877, (2009). [4] British Pharmcopia, Her Majesty s Stationery Office, London, UK (2000) [5] Posac, J.R., Vasquez, M.D., Tascon, M.L., Sanchez, B.P.: Determination of aceclofenac using adsorptive stripping voltammetric techniques on conventional and surfactant chemically modified carbon paste electrodes. Talanta 42, (1995). [6]El-Kousy, N.M.: Spectrophotometric and spectrofluorimetric determination of etodolac and aceclofenac. Pharm. Biomed. Anal. 20, (1999). [7] Gao, L.Q., Liu, W.Y., Xing, J.D., Zazhi, Y.F.: Simultaneous Estimation of Aceclofenac and Paracetamol in Synthetic Mixture by Q-Analysis UV Spectrophotometric Method. J pharmatutor. 18, (1998). [8] Lee, H.S., Jeong, C.K., Choi, S.J., Kim, S.B., Lee, M.H., Ko, G.I., Shon, D.H.: Simultaneous determination of aceclofenac and diclofenac in human plasma by narrowbore HPLC using column-switching. Pharm. Biomed. Anal. 23, (2000). [9] Rodionova, O.Y., Houmøller, L.P., Pomerantsev, A.L., Geladi, P., Burger, J., Dorofeyev, V.L., Arzamastsev, A.P.: NIR spectrometry for counterfeit drug detection: A feasibility study. Anal. Chim. Acta. 549, (2005). [10] Sherazi, S.T.H., Ali, M., Mahesar, S.A.: Application of Fourier-transform infrared (FT-IR) transmission spectroscopy for the estimation of roxithromycin in pharmaceutical formulations. Vibrational Spectroscopy. 55, (2011). [11] AOAC International, AOAC Guidelines for Single Laboratory Validation of Chemical Methods for Dietary Supplements and Botanicals, Association of Official Analytical Chemists, Arlington, VA (2002). 2 21

7 Quantitative estimation of aceclofenac and its pharmaceutical formulations using FTIR spectroscopy Nimmala Anvesh Reddy, a R. Lakshmipathy, b G. Venugopala Rao, a NC.Sarada a* a Environmental and Analytical chemistry division, School of advanced sciences, VIT University, Vellore, Tamilnadu, India b Department of Chemistry, KCG College of Technology, Karapakkam, Chennai, Tamilnadu, India Supplementary information Table.1 Analysis of Aceclofenac commercial formulation (Tablets) Sample Labeled claim (mg) Amount recovered Recovery (%) Sample Sample Sample Table.2 Recovery test of Aceclofenac from tablet samples after exogenous addition of known amount of standards By FTIR spectroscopy Acceptable recovery (%) Sample A B C Recovery (%) [11] A-Exogenous addition, B-Before addition, C-After addition Table 3 Comparison of recovery % with other analytical techniques Analytical Technique Tablet recovery%±%r.s.d Standard addition ±%R.S.D Reference Spectrometric 98.81± ±0.51 [6] Densitometric 99.68± ±.74 [1] HPLC 99.50± ±0.64 [7] FTIR 98.91± ±0.59 This study