A Single Gradient Stability-Indicating Reversed-Phase LC Method for the Estimation of Impurities in Omeprazole and Domperidone Capsules

Analytical quality by design-based development of a capillary electrophoresis method for Omeprazole impurity profiling

Omeprazole (OME) is a proton pump inhibitor used to treat gastroesophageal reflux disease associated conditions. The current study presents an Analytical Quality by Design-based approach for the development of a CE method for OME impurity profiling. The scouting experiments suggested the selection of solvent modified Micellar ElectroKinetic Chromatography operative mode using a pseudostationary phase composed of sodium dodecyl sulfate (SDS) micelles and n-butanol as organic modifier in borate buffer. A symmetric three-level screening matrix 37//16 was used to evaluate the effect of Critical Method Parameters, including Background Electrolyte composition and instrumental settings, on Critical Method Attributes (critical resolution values, OME peak width and analysis time). The analytical procedure was optimized using Response Surface Methodology through a Central Composite Orthogonal Design. Risk of failure maps made it possible to define the Method Operable Design Region, within which the following optimized conditions were selected: 72 mM borate buffer pH 10.0, 96 mM SDS, 1.45 %v/v n-butanol, capillary temperature 21 °C, applied voltage 25 kV. The method was validated according to ICH guidelines and robustness was evaluated using a Plackett-Burman design. The developed procedure enables the simultaneous determination of OME and seven related impurities, and has been successfully applied to the analysis of pharmaceutical formulations.

Potential factors of Helicobacter pylori resistance to clarithromycin

OBJECTIVES

A comparative dissolution kinetics test (CDKT) and bioequivalence studies of generic proton pump inhibitors (PPIs) do not model pharmacological acid suppression (PAS) and pathological duodenogastric reflux (PDGR). This study aimed to model them in CDKT to assess drugs stability and potential pantoprazole-clarithromycin interactions.

METHODS

In CDKT, PDGR (dissolution medium pH 7.00 ± 0.05, preexposure at pH 1.20 ± 0.05) and PAS (pH 4.00 ± 0.05) were modelled for original pantoprazole (OP) and its generics (GP1-4). In CDKT with high-performance liquid chromatography, dissolution gastric medium in adequate (pH 4.00 ± 0.05) and inadequate (pH 1.20 ± 0.05) PAS were modelled for original clarithromycin (OC) and its generics (GC1-4).

RESULTS

After exposure in pH 7.00 ± 0.05, pantoprazole was released from GP1 within 10 min in the amount of 68.8%. In рН 4.00 ± 0.05, 83.0% and 81.5% of pantoprazole were released from GP1 and GP4. When OP, GP2 and GP3 were placed in pH 7.00 ± 0.05, pantoprazole was released in amount: 99.4%, 88.0% and 98.2%. Clarithromycin releasing from OC, GC1, GC2, GC3, GC4 in pH 4.00 ± 0.05 was 93.5%, 91.6%, 92.9%, 79.4% and 83.0%. In pH 1.20 ± 0.05: 9.7%, 6.7%, 8.5%, 33.3%, 28.8%.

CONCLUSIONS

Destruction of enteric coats of some local pantoprazole generics in CDKT-models might be a potential factor for inadequate therapy.

Separation of Unprecedented Degradants of Domperidone by Ultra-Performance Convergence Chromatography and Their Structure Elucidation

Domperidone, a gastroprokinetic agent, is a common drug to treat emesis. It was subjected to acid, base-mediated hydrolysis, peroxide-mediated oxidation, photolysis and thermal degradation according to ICH guidelines to observe stability of the selected drug under the stress conditions. Although the drug is resistant to base hydrolysis, photolysis and thermal stressors, two degradants (DP-ISO1 and DP-ISO2) were formed in acid mediated hydrolysis. Oxidation with hydrogen peroxide also resulted in one product (DP-OX). All three degradants were isolated from the crude reaction mixture by preparative high-performance liquid chromatography and supercritical fluid chromatography. Structures of isolated compounds were unambiguously characterized as 5-chloro-1-(1-(3-(6-chloro-2-oxo-2,3-dihydro-1H-benzo[d]imidazol-1-yl)propyl)piperidin-4-yl)-1,3-dihydro-2H-benzo[d]imidazol-2-one (DP-ISO1), 5-chloro-1-(3-(4-(5-chloro-2-oxo-2,3-dihydro-1H-benzo[d]imidazol-1-yl)piperidin-1-yl)propyl)-1,3-dihydro-2H-benzo[d]imidazol-2-one (DP-ISO2), 4-(5-chloro-2-oxo-2,3-dihydro-1H-benzo[d]imidazol-1-yl)-1-(3-(2-oxo-2,3-dihydro-1H-benzo[d]imidazol-1-yl)propyl)piperidine 1-oxide (DP-OX) by analysis of mass spectrometry, 1D and 2D nuclear magnetic resonance spectra. To the best of our knowledge, DP-ISO1 and DP-ISO2 are new and DP-OX was previously reported as domperidone impurity.

Identification and structural characterization of the stress degradation products of omeprazole using Q-TOF-LC-ESI-MS/MS and NMR experiments: evaluation of the toxicity of the degradation products

Omeprazole (OMP), a prototype proton pump inhibitor used for the treatment of peptic ulcers and gastroesophageal reflux disease (GERD), was subjected to forced degradation studies as per ICH guidelines Q1A (R2).

Development and Validation of a Novel Stability-Indicating RP-HPLC Method for the Simultaneous Determination of Related Substances of Ketoprofen and Omeprazole in Combined Capsule Dosage Form

A novel, simple, sensitive, selective and reproducible stability-indicating high performance liquid chromatographic method was developed for the quantitative determination of degradation products and process-related impurities of ketoprofen (KET) and omeprazole (OMZ) in combined oral solid dosage form. Chromatographic separation was achieved on a Phenomenex Luna C18 (2) column (150 × 4.6 mm, 5 μm) under gradient elution by using a binary mixture of potassium dihydrogen phosphate buffer and acetonitrile at a flow rate of 0.8 mL/min. Chromatogram was monitored at 233 nm for KET impurities and at 305 nm for OMZ impurities using a dual wavelength UV detector. Resolution for KET and OMZ and 14 impurities was found to be >1.5 for any pair of components. Typical retention behaviors of impurities at various pH values were depicted graphically. To prove the stability-indicating power of the method, the drug product was subjected to hydrolytic, oxidative, photolytic, humidity and thermal stress conditions as per ICH. The developed method was validated according to the current ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, ruggedness and robustness.

Development of RP UPLC-TOF/MS, stability indicating method for omeprazole and its related substances by applying two level factorial design; and identification and synthesis of non-pharmacopoeial impurities

A new UPLC-TOF/MS compatible, reverse phase-stability indicating method was developed for determination of Omeprazole (OMP) and its related substances in pharmaceutical dosage forms by implementing Design of Experiment (DoE) i.e. two level full factorial Design (2(3)+3 center points=11 experiments) to understand the Critical Method Parameters (CMP) and its relation with Critical Method Attribute (CMA); to ensure robustness of the method. The separation of eleven specified impurities including conversion product of OMP related compound F (13) and G (14) i.e. Impurity-I (1), OMP related compound-I (11) and OMP 4-chloro analog (12) was achieved in a single method on Acquity BEH shield RP18 100 × 2.1 mm, 1.7 μm column, with inlet filter (0.2 μm) using gradient elution and detector wavelength at 305 nm and validated in accordance with ICH guidelines and found to be accurate, precise, reproducible, robust and specific. The drug was found to degrade extensively in heat, humidity and acidic conditions and forms unknown degradation products during stability studies. The same method was used for LC-MS analysis to identify m/z and fragmentation of maximum unknown impurities (Non-Pharmacopoeial) i.e. Impurity-I (1), Impurity-III (3), Impurity-V (5) and Impurity-VIII (9) formed during stability studies. Based on the results, degradation pathway for the drug has been proposed and synthesis of identified impurities i.e. impurities (Impurity-I (1), Impurity-III (3), Impurity-V (5) and Impurity-VIII (9)) are discussed in detail to ensure in-depth understanding of OMP and its related impurities and optimum performance during lifetime of the product.

The ultra-performance liquid chromatography determination of domperidone and its process-related impurities

A rapid ultra-performance liquid chromatography (UPLC) method for the determination of domperidone in the presence of its process impurities and droperidol was developed and validated. The rapid chromatographic separation was achieved using a sub 2 µm Hypersil Zorbax eXtra Densely Bonded C18 column (30 × 4.6 mm, i.d., 1.8 µm). A gradient mobile phase consisting of Solvent A: 0.06 M ammonium acetate and Solvent B: methanol, with a flow rate of 1 mL/min was employed. The column temperature was set at 40°C, and the diode-array detector was set at 280 nm. An injection volume of 3 µL was used. The currently utilized European Pharmacopeia (Eur. Pharm.) method employed by Janssen Pharmaceuticals Ltd was run on a Hypersil Base-Deactivated Silica C18 column (100 × 4.6 mm, i.d., 3 µm) with a run time of 12.5 min. The developed UPLC method, with a run time of 7.5 min was determined to be accurate, precise, specific, robust and highly sensitive according to the International Conference on Harmonization guidelines. The method herein demonstrated a reduction in analysis time of 40%, allowing for a much higher sample throughput. A solvent consumption decrease of over 58% was also observed, which results in a dramatic reduction in running costs for Janssen Pharmaceuticals Ltd.

Design of Experiment (DOE) Utilization to Develop a Simple and Robust Reversed-Phase HPLC Technique for Related Substances' Estimation of Omeprazole Formulations

A simple, fast, and sensitive reversed-phase HPLC method with UV detection was developed for the quantitation of omeprazole and its eleven related compounds (impurities) in pharmaceutical formulation using the Thermo Accucore C–18 (50 mm × 4.6 mm, 2.6 μm) column. The separation among all the compounds was achieved with a flow rate of 0.8 mL min⁻¹ employing a gradient program of mobile phase A [0.08 M glycine buffer pH 9.0: acetonitrile; 95:05 (v/v)] and mobile phase B [acetonitrile: methanol; 65:35 (v/v)]. The chromatographic detection was carried out at a wavelength of 305 nm. The method was validated for specificity, linearity, and recovery. The huskiness of the method was determined prior to validation using the Design of Experiments (DOE). The ANOVA analysis of DOE with a 95% confidence interval (CI) confirmed the buffer pH of mobile phase A (p <0.0001) and column temperature (p<0.0001) as significant Critical Method Parameters (CMPs).