EXPERIMENTALLY DESIGNED, VALIDATED HPLC SIMULTANEOUS DETERMINATION OF PRIDINOL AND DICLOFENAC IN THEIR COMBINED PHARMACEUTICAL FORMULATIONS, WHICH ALLOWS LIMITING DICLOFENAC RELATED COMPOUND A

Concurrent Determination of Pridinol, Diclofenac and Impurity A by HPLC-UV

A reversed-phase high-performance liquid chromatography method was developed and validated for the simultaneous determination of pridinol, diclofenac and diclofenac-related compounds in tablet formulations. The proposed method is also suitable for content uniformity determination, for dissolution test and for stability studies. Separation was achieved on a base-deactivated silica C8 column, using 50 mM phosphate buffer (pH 2.5) and methanol (40:60 v/v) as mobile phase, at a flow rate of 1.0 mL/min and column temperature of 40°C. Ultraviolet detection was made at 225 nm. The method was validated for specificity, accuracy, precision (intraday and interday levels) and linearity for each analyte. For diclofenac impurity A, sensitivity was also studied. The method showed specificity and linearity (R2: 0.999 for the three analytes) over the assessed concentration range (diclofenac: 2.5-75.0 μg/mL, pridinol: 2.0-60.0 μg/mL and impurity A: 1.25-5.0 μg/mL) and demonstrated good precision as reflected by the low coefficient of variation in all cases. Recovery rates obtained were 99.81, 100.58 and 100.96% for diclofenac, pridinol and impurity A respectively, and for all three analytes, the variances of the concentrations tested were equivalent. The detection and quantitation limits for impurity A were 0.078 and 0.261 μg/mL, respectively.

Validation of an HPLC Method for the Determination of Diclofenac Diethylamine and Three of Its Impurities in a Gel Pharmaceutical Form

BACKGROUND

Monitoring impurities in drug products is a principal requirement of pharmaceutical regulatory authorities all over the world to ensure drug safety. For this reason, there is a great need for analytical QC of dugs products.

OBJECTIVE

In this study, a simple, efficient, and direct HPLC method was developed for the determination of three impurities of diclofenac.

METHODS

The HPLC method was developed using a mobile phase which consisted of an HPLC grade mixture, acetonitrile-0.01M phosphoric acid adjusted to pH 2.3 (1 + 3, by volume).

RESULTS

The separation was performed in 15 min. The calibration curves of the three impurities were linear; the correlation coefficients were 0.999 at concentrations of 0.00015-0.003 µg/mL.

CONCLUSION

The validation of this method shows that it meets all validation criteria. This shows the reliability of this method for the routine control of diclofenac impurities.

HIGHLIGHTS

The validation of a robust HPLC method for the determination of diclofenac impurities is of great importance for the pharmaceutical industry to control its products.

A comprehensive strategy in the development of a cyclodextrin-modified microemulsion electrokinetic chromatographic method for the assay of diclofenac and its impurities: Mixture-process variable experiments and quality by design

A comprehensive strategy involving the use of mixture-process variable (MPV) approach and Quality by Design principles has been applied in the development of a capillary electrophoresis method for the simultaneous determination of the anti-inflammatory drug diclofenac and its five related substances. The selected operative mode consisted in microemulsion electrokinetic chromatography with the addition of methyl-β-cyclodextrin. The critical process parameters included both the mixture components (MCs) of the microemulsion and the process variables (PVs). The MPV approach allowed the simultaneous investigation of the effects of MCs and PVs on the critical resolution between diclofenac and its 2-deschloro-2-bromo analogue and on analysis time. MPV experiments were used both in the screening phase and in the Response Surface Methodology, making it possible to draw MCs and PVs contour plots and to find important interactions between MCs and PVs. Robustness testing was carried out by MPV experiments and validation was performed following International Conference on Harmonisation guidelines. The method was applied to a real sample of diclofenac gastro-resistant tablets.

A novel stability-indicating UPLC method development and validation for the determination of seven impurities in various diclofenac pharmaceutical dosage forms

An innovative simple, fast, precise and accurate ultra-high performance liquid chromatography (UPLC) method was developed for the determination of diclofenac (Dic) along with its impurities including the new dimer impurity in various pharmaceutical dosage forms. An Acquity HSS T3 (C18, 100×2.1mm, 1.8μm) column in gradient mode was used with mobile phase comprising of phosphoric acid, which has a pH value of 2.3 and methanol. The flow rate and the injection volume were set at 0.35ml·min(-1) and 1μl, respectively, and the UV detection was carried out at 254nm by using photodiode array detector. Dic was subjected to stress conditions from acid, base, hydrolytic, thermal, oxidative and photolytic degradation. The new developed method was successfully validated in accordance to the International Conference on Harmonization (ICH) guidelines with respect to specificity, limit of detection, limit of quantitation, precision, linearity, accuracy and robustness. The degradation products were well resolved from main peak and its seven impurities, proving the specificity power of the method. The method showed good linearity with consistent recoveries for Dic content and its impurities. The relative percentage of standard deviation obtained for the repeatability and intermediate precision experiments was less than 3% and LOQ was less than 0.5μg·ml(-1) for all compounds. The new proposed method was found to be accurate, precise, specific, linear and robust. In addition, the method was successfully applied for the assay determination of Dic and its impurities in the several pharmaceutical dosage forms.

Manipulating ratio spectra for the spectrophotometric analysis of diclofenac sodium and pantoprazole sodium in laboratory mixtures and tablet formulation

Objective. Three sensitive, selective, and precise spectrophotometric methods based on manipulation of ratio spectra, have been developed and validated for the determination of diclofenac sodium and pantoprazole sodium. Materials and Methods. The first method is based on ratio spectra peak to peak measurement using the amplitudes at 251 and 318 nm; the second method involves the first derivative of the ratio spectra (Δλ = 4 nm) using the peak amplitudes at 326.0 nm for diclofenac sodium and 337.0 nm for pantoprazole sodium. The third is the method of mean centering of ratio spectra using the values at 318.0 nm for both the analytes. Results. All the three methods were linear over the concentration range of 2.0–24.0 μg/mL for diclofenac sodium and 2.0–20.0 μg/mL for pantoprazole sodium. The methods were validated according to the ICH guidelines and accuracy, precision, repeatability, and robustness are found to be within the acceptable limit. The results of single factor ANOVA analysis indicated that there is no significant difference among the developed methods. Conclusions. The developed methods provided simple resolution of this binary combination from laboratory mixtures and pharmaceutical preparations and can be conveniently adopted for routine quality control analysis.