Separation and determination of impurities in paracetamol, codeine and pitophenone in the presence of fenpiverinium in combined suppository dosage form

A Validated Method for Separation and Determination of Codeine Phosphate Hemihydrate Impurities in Bilayer Tablet Dosage Form of Naproxen Sodium and Codeine Phosphate by Using UHPLC

Background:

Apranax Plus® is a new bilayer tablet dosage form, which combines two active pharmaceutical ingredients: naproxen sodium and codeine phosphate.

Objective:

The purpose of this work was to develop an ultra-high-performance liquid chromatography (UHPLC) method for the separation and determination of codeine phosphate hemihydrate impurities in a bilayer tablet dosage form.

Methods:

The separation and determination of codeine phosphate hemihydrate and its impurities, methylcodeine, morphine, codeine dimer, 10-hydroxycodeine, 14-hydroxycodeine, thebaine and codeinone were achieved by using reversed-phase liquid chromatography with TUV (Tunable UV Detector) and PDA (Photodiode Array Detector) detection by UHPLC. The new proposed method utilized by the Waters Acquity UHPLC® TUV and PDA systems using a UHPLC column Waters Acquity, BEH, C18, 2.1x100 mm, 1.7 μm particle size with a mixture of component A and acetonitrile in a gradient mode at a flow rate of 0.3mL/min, at 25°C with a load of 5μL. The detection for all eluted compounds was carried out at 245nm.

Results:

The codeine phosphate hemihydrate and peaks of its impurities were adequately obtained, thus proving the stability-indicating power of the method. The developed method was validated as per the ICH guidelines with respect to parameters such as precision, accuracy, linearity, limit of detection (LOD), limit of quantification (LOQ) and robustness.

Conclusion:

It was verified as being adequate for all the mentioned impurities of codeine phosphate hemihydrate. The described method was found to be useful for routine purity testing and was also found suitable for the analysis of the stability samples of the drug product.

Validated specific HPLC-DAD method for simultaneous estimation of paracetamol and chlorzoxazone in the presence of five of their degradation products and toxic impurities

This work demonstrates a specific and reliable HPLC with diode array detection (DAD) method for the simultaneous estimation of paracetamol (PAR) and chlorzoxazone (CZ) in the presence of five of their degradation products and toxic impurities; namely; 4-aminophenol (AP), 4-nitrophenol (NP), acetanilide (AT), 4-chloroacetanilide (CA) and 2-amino-4-chlorophenol (ACP). Successful chromatographic separation was accomplished using Waters Symmetry C8 column (3.9 × 150 mm, 5 μm) with gradient elution of the mobile phase consisting of 0.05 M phosphate buffer pH 7.5 and methanol. The gradient elution started with 5% (by volume) methanol ramped up linearly to 50% in 10 min, and then maintained at this percentage afterward till the end of the run. The mobile phase was pumped at a flow rate of 1.0 mL/min. The multiple wavelength detector was adjusted at 244 and 285 nm to quantify PAR and CZ, respectively. Additionally, the wavelength 270 nm was found suitable for monitoring the separation of the entire mixture of PAR, CZ, and their impurities. Seven peaks eluted with excellent resolution at retention times 3.4, 5.7, 8.0, 10.1, 10.8, 13.5, and 14.4 min for AP, PAR, NP, AT, ACP, CZ, and CA, respectively. Performance of the proposed method was validated with respect to linearity, range, precision, accuracy, specificity, robustness, detection, and quantitation limits. Calibration curves were linear in the ranges of 10-75 and 10-100 µg/mL for PAR and CZ, respectively with correlation coefficients not less than 0.9998. The proposed method proved to be specific and stability indicating by the resolution of both drugs from their degradation products and toxic impurities. Validated HPLC method was successfully applied to the analysis of PAR and CZ in their combined capsules dosage form, and assay results were favorably compared with a published reference HPLC method. DAD served as an efficient tool for peak identity and purity verification.

Advancing USP compendial methods for fixed dose combinations: A case study of metoprolol tartrate and hydrochlorothiazide tablets

The current United States Pharmacopeia–National Formulary (USP–NF) includes more than 250 monographs of fixed dose combinations (FDCs), and some of them need to be updated due to incompleteness of impurity profiles and obsolescence of analytical methodologies. A case study of metoprolol tartrate and hydrochlorothiazide tablets is presented to summarize challenges encountered during the USP monograph modernization initiative of FDCs and to highlight an “adoption and adaptation” approach employed for method development. To this end, a single stability-indicating HPLC method was developed to separate the two drug substances and eight related compounds with resolution 2.0 or higher between all critical pairs. Chromatographic separations were achieved on a Symmetry column (C₁₈, 100 mm × 4.6 mm, 3.5 µm) using sodium phosphate buffer (pH 3.0; 34 mM) and acetonitrile as mobile phase in a gradient elution mode. The stability-indicating capability of this method has been demonstrated by analyzing stressed samples of the two drug substances. The developed HPLC method was validated for simultaneous determination of metoprolol tartrate and hydrochlorothiazide and relevant impurities in the tablets. Moreover, the developed method was successfully applied to the analysis of commercial tablet dosage forms and proved to be suitable for routine quality control use. The case study could be used to streamline USP's monograph modernization process of FDCs and strengthen compendial procedures.

Derivative synchronous spectrofluorimetry: Application to the analysis of two binary mixtures containing codeine in dosage forms

Two binary mixtures containing codeine (COD) with either ibuprofen (IBU), mixture 1, or with phenylephrine hydrochloride (PE), mixture 2, were analyzed using three simple eco-friendly spectrofluorimetric methods without the need to a prior separation step. The first method is derivative emission spectrofluorimetry using λ_ex = 236 nm and 275 nm for mixtures 1 and 2, respectively. The second method is constant-wavelength synchronous spectrofluorimetry using ∆λ = 100 nm and 60 nm for mixtures 1 and 2, respectively. The last method is constant-energy synchronous spectrofluorimetry where a wave number interval of -7000 cm^-1 was used for the analysis of the two binary mixtures. All measurements were performed in acetate buffer pH 5 and thus no toxic volatile solvents were used increasing method greenness. High sensitivity was attained for the three studied drugs where the lower limits of quantitation of COD, IBU and PE reached 0.064, 0.512 and 0.087 μg/mL, respectively. Analysis of the two binary mixtures in their tablet and liquid dosage forms was performed with good accuracy and precision using the developed methods. The results of the proposed and reported methods were statistically evaluated using one-way ANOVA test and no significant difference among them was obtained. In addition, all aspects of ICH guidelines on analytical method validation were conducted.

Fast determination of codeine, orphenadrine, promethazine, scopolamine, tramadol, and paracetamol in pharmaceutical formulations by capillary electrophoresis

Paracetamol is an active ingredient commonly found in pharmaceutical formulations in combination with one of the following compounds: codeine, orphenadrine, promethazine, scopolamine, and tramadol. In this work, we propose a unique analytical method for determination of these active ingredients in pharmaceutical samples. The method is based on capillary electrophoresis with capacitively coupled contactless conductivity detection. The separation was achieved on a fused silica capillary (50 cm total length, 40 cm effective length, and 50 μm id) using an optimized background electrolyte composed of 20 mmol/L β-alanine/4 mmol/L sodium chloride/4 μmol/L sodium hydroxide (pH 9.6). Each sample can be analyzed in a single run (≤2 min) and the limits of detection were 2.5, 0.62, 0.63, 2.5, 15, and 1.6 μmol/L for scopolamine, tramadol, orphenadrine, promethazine, codeine, and paracetamol, respectively. Recovery values for spiked samples were between 94 and 104%.