Stability-indicating HPLC and PLS chemometric methods for the determination of acemetacin in presence of its degradation products and impurities

Abstract

Two stability-indicating methods were developed and validated for the quantitative determination of acemetacin (ACM) in presence of its degradation products and impurities. The first method was based on separation of ACM from its degradation products and impurities by RP-HPLC on Inertsil C8 column (150 × 4.6 mm i.d) using a mobile phase composed of 0.02 M phosphate buffer: methanol (35:65, v:v, pH = 6.5). The flow rate was adjusted at 1 mL/min and quantification was achieved with UV detection at 245 nm using meloxicam as internal standard. The second method was based on multivariate spectrophotometric analysis using partial least square regression model. The drug was subjected to acid, base, oxidative and thermal stress conditions and the degradation products were identified. The developed methods have the requisite accuracy, selectivity, sensitivity and precision to assay ACM in presence of its degradation products and impurities either in bulk powder or in pharmaceutical dosage form. The results obtained for the analysis of ACM in its pure form by the proposed methods were statistically compared to those obtained by applying a reported HPLC method. The statistical comparison showed that there is no significant difference between the proposed methods and the reported one with respect to accuracy and precision.

Ultra-performance liquid chromatography coupled to electrospray ionization-tandem mass spectrometric method for simultaneous determination of acemetacin in presence of its metabolite indomethacin and degradation products

“…The British Pharmacopoeia [9] described indomethacin and p-chlorobenzoic acid (PCBA) as impurities for ACM. p-Chlorobenzoic acid and 5-methoxy-2-methyl-3-indole acetic acid are reported as the degradation products under specific alkaline and acidic stress conditions [5]. These degradation products obtained were confirmed by their m/z using UPLC-MS/MS.…”

“…ACM under different stressed acidic (reflux with 0.1 N HCl for 3 hrs in boiling water bath) and basic (0.1 N NaOH for 30 min at room temperature) conditions undergo complete degradation, where it is stable under oxidative and thermal stress conditions as reported [5]. ACM was degradated into PCBA and 5-methoxy-2-methyl-3-indole acetic acid as reported [5], which confirmed by their molecular weights m/z 156.32, 220.30 using the proposed method (Full scan). So, by applying the proposed UPLC-MS/MS technique, it was probable to detect ACM in the presence of its metabolite and/or degradation products in short time (˂ 1 min) as shown in Figure 2.…”

“…The accuracy of the proposed method was evaluated by assay of ACM standard solutions by the proposed method and the results obtained were compared with those obtained using the reported one [5]. Statistical analysis of the results obtained by the proposed and reported methods using student´s t-test and variance ratio F-test, showed no significant difference between the two methods ( Table 2).…”

“…Standard stock solutions of 100 µg/mL for ACM and indomethacin were prepared separately in methanol and stored in refrigerator. Sample degradation: ACM pure sample was subjected to forced degradation under different stressed conditions as, alkaline (0.1 N NaOH for 30 min at room temperature) or acidic (reflux with 0.1 N HCl for 3 hrs in boiling water bath) then neutralized as reported [5].…”

“…Literature survey reveals that there are several methods have been investigated for the determination of ACM, such as spectrophotometric [2][3][4], chromatographic [2][3][4][5][6] and voltammetric methods [7,8]. The British Pharmacopoeia [9] described indomethacin and p-chlorobenzoic acid (PCBA) as impurities for ACM.…”