Strategy for developing and optimizing liquid chromatography methods in pharmaceutical development using computer-assisted screening and Plackett–Burman experimental design

Separation and identification of degradation impurities of esomeprazole sodium

Drug impurities are important factors that affect drug safety and efficacy. The aim of this study is to separate and confirm the structure of two degradation impurities of esomeprazole sodium, designated X and Y. The impurities X and Y were successfully isolated using preparative HPLC by developing separation methods with the help of ACD/Labs AutoChrom software. There was a steady increase in X and Y impurities in forced esomeprazole sodium degradation. Impurity X was confirmed as 6-methoxy-1h-benzo[d]imidazole-2-yl-4-amino-3,5-dimethylpyridinecarboxylate and impurity Y as 6-methoxy-1h-benzo[d]imidazole-2-yl-4-hydroxy-3,5-dimethylpyridinecarboxylate using nuclear magnetic resonance spectrometry, infrared spectroscopy, and high-resolution mass spectrometry. These findings provide a comprehensive understanding of the impurity profile of esomeprazole sodium because these impurities are reported for the first time. Based on our results, active pharmaceutical ingredient manufacturers can further control process parameters to reduce impurity generation, and drug production manufacturers can optimize the packaging and storage conditions of esomeprazole sodium.

Quality by Design: Concept to Applications

BACKGROUND

Quality by Design (QbD) is associated with a modern, systematic, scientific and novel approach which is concerned with pre-distinct objectives that not only focus on product, process understanding but also lead to process control. It predominantly signifies the design and product improvement and the manufacturing process in order to fulfill the predefined manufactured goods or final products quality characteristics. It is quite essential to identify the desired and required product performance report, such as Target Product Profile, typical Quality Target Product Profile (QTPP) and Critical Quality Attributes (CQA).

METHODS

This review highlighted the concepts of QbD design space, for critical material attributes (CMAs) as well as the critical process parameters that can totally affect the CQAs within which the process shall be unaffected thus, consistently manufacturing the required product. Risk assessment tools and design of experiments are its prime components.

RESULTS

This paper outlines the basic knowledge of QbD, the key elements; steps as well as various tools for QbD implementation in pharmaceutics field are presented briefly. In addition to this, quite a lot of applications of QbD in numerous pharmaceutical related unit operations are discussed and summarized.

CONCLUSION

This article provides a complete data as well as the roadmap for universal implementation and application of QbD for pharmaceutical products.

Improved Understanding of the High Shear Wet Granulation Process under the Paradigm of Quality by Design Using Salvia miltiorrhiza Granules

BACKGROUND

High shear wet granulation (HSWG) is a shaping process for granulation that has been enhanced for application in the pharmaceutical industry. However, study of HSWG is complex and challenging due to the relatively poor understanding of HSWG, especially for sticky powder-like herbal extracts.

AIM

In this study, we used Salvia miltiorrhiza granules to investigate the HSWG process across different scales using quality by design (QbD) approaches.

METHODS

A Plackett-Burman experimental design was used to screen nine granulation factors in the HSWG process. Moreover, a quadratic polynomial regression model was established based on a Box-Behnken experimental design to optimize the granulation factors. In addition, the scale-up of HSWG was implemented based on a nucleation regime map approach.

RESULTS

According to the Plackett-Burman experimental design, it was found that three granulation factors, including salvia ratio, binder amount, and chopper speed, significantly affected the granule size (D50) of S. miltiorrhiza in HSWG. Furthermore, the results of the Box-Behnken experimental design and validation experiment showed that the model successfully captured the quadratic polynomial relationship between granule size and the two granulation factors of salvia ratio and binder amount. At the same experiment points, granules at all scales had similar size distribution, surface morphology, and flow properties.

CONCLUSIONS

These results demonstrated that rational design, screening, optimization, and scale-up of HSWG are feasible using QbD approaches. This study provides a better understanding of HSWG process under the paradigm of QbD using S. miltiorrhiza granules.

Application of the Principles of Green Chemistry for the Development of a New and Sensitive Method for Analysis of Ertapenem Sodium by Capillary Electrophoresis

An innovative method is validated for the analysis of ertapenem sodium by capillary electrophoresis using potassium phosphate buffer 10 mM pH 7 and 15 kV voltage, in the concentration range of 70 to 120 μg mL⁻¹. Ertapenem had a migration time of 3.15 minutes and the linearity curve was y = 2281.7 x - 24495 with a R² = 0.9994. Thus, we propose a routine analysis method that meets the principles of green analytical chemistry for the routine analysis of ertapenem sodium by capillary electrophoresis.

Establishment and reliability evaluation of the design space for HPLC analysis of six alkaloids in Coptis chinensis (Huanglian) using Bayesian approach

Coptis chinensis (Huanglian) is a commonly used traditional Chinese medicine (TCM) herb and alkaloids are the most important chemical constituents in it. In the present study, an isocratic reverse phase high performance liquid chromatography (RP-HPLC) method allowing the separation of six alkaloids in Huanglian was for the first time developed under the quality by design (QbD) principles. First, five chromatographic parameters were identified to construct a Plackett-Burman experimental design. The critical resolution, analysis time, and peak width were responses modeled by multivariate linear regression. The results showed that the percentage of acetonitrile, concentration of sodium dodecyl sulfate, and concentration of potassium phosphate monobasic were statistically significant parameters (P < 0.05). Then, the Box-Behnken experimental design was applied to further evaluate the interactions between the three parameters on selected responses. Full quadratic models were built and used to establish the analytical design space. Moreover, the reliability of design space was estimated by the Bayesian posterior predictive distribution. The optimal separation was predicted at 40% acetonitrile, 1.7 g·mL(-1) of sodium dodecyl sulfate and 0.03 mol·mL(-1) of potassium phosphate monobasic. Finally, the accuracy profile methodology was used to validate the established HPLC method. The results demonstrated that the QbD concept could be efficiently used to develop a robust RP-HPLC analytical method for Huanglian.

Levels in the interpretive optimisation of selectivity in high-performance liquid chromatography: A magical mystery tour

Interpretive approaches for selectivity optimisation, which are those supported by retention models, are able to exploit efficiently the capabilities of the chromatographic system. The resolution of a mixture is usually faced in a first trial by looking for a unique experimental condition, able to resolve all compounds in the sample. If this is not possible, the problem can be outlined with less ambitious aims, focusing on only some compounds. In an extreme case, a single analyte can be individually optimised. Current strategies that give answer to the different goals pursued in the analysis, which are classified as total, partial and specific, are reviewed. Optimisation oriented to deconvolution, useful in case of partial coelution, and robust measurements of resolution, are also outlined. The steps recognised in any chromatographic optimisation procedure, and some fundamentals and tools used in optimisation approaches for isocratic and gradient elution are commented to explain different strategies. Examples of increasing complexity are supplied to explain the problematic arose, and the convenience in applying a certain methodology. Details on the mathematical treatment for each particular optimisation strategy are also given.

Development of a removable multi-column-switching system for gas chromatography

A removable column-switching device for a commercially available gas chromatograph has been developed. To this end, the challenges of the equipment's high temperature stability, of the flow of gas through stand-by columns, of catalytically effective stainless steel surfaces, of the cooling trap effects within valves and the limited oven space are dealt with. The developed column-switching system was investigated in terms of dead volume (tailing factor), adsorption (Grob test) and degradation (Endrin test). This GC column-switching system shows comparable results with analyses that do not employ column switching. For example, it was possible to avoid effects, such as adsorption and decomposition. This system can automatically test the suitability of as many as eight separating columns to analyze unknown samples. The GC column-switching system thus serves to increase efficiency in the selection or screening of stationary phases with GC method developments.

Determination of topiramate and its degradation product in liquid oral solutions by high performance liquid chromatography with a chemiluminescent nitrogen detector

Topiramate is a sulfamate-substituted monosaccharide that is prescribed for the treatment of epilepsy. It has been a challenge to develop analytical methods for topiramate formulations because the compounds of interest do not have chromophores that are active above 190 nm and because of interference from excipients. This paper describes a simple, specific, precise, accurate, and sensitive method using a chemiluminescent nitrogen detector. The method has a validated linearity range of 32-4800 ng of topiramate and excellent precision (system repeatability). The limit of quantitation was determined to be 0.1% for the degradation product w/w versus topiramate. The method has been successfully used for probe stability studies in support of early phase formulation development.

Sample preparation optimization for assay of active pharmaceutical ingredients in a transdermal drug delivery system using experimental designs

A simple but very effective sample preparation method is discussed for a matrix or drug-in-adhesive type of transdermal drug delivery system (TDS). The method is a one-step extraction using a methanol/water solvent system. Because of the unique design and physical property of the delivery system, special considerations were taken in selection of sample solvent, sample container and extraction enhancement device. The main focus of the article is on method optimization using experimental designs. A Plackett-Burman design was used to screen multiple method factors including extraction solvent strength, extraction solvent volume, shaking speed of a reciprocating shaker, and shaking time. Later, two of the factors were studied in more details using a 4 x 5 general factorial design. From the experimental results, the so-called main effects plots and interaction plots were generated using a statistical software. The plots are helpful in choosing the method conditions.