Green approach using monolithic column for simultaneous determination of coformulated drugs

Green spectrophotometric approaches applied to tertiary mixture for management of common cold and COVID-19 symptoms

Recently, cold and cough dosage forms have gained significant attention due to their use in the supportive protocols for managing COVID-19 symptoms. In this study, a pharmaceutical formulation containing Paracetamol (PAR), Guaifenesin (GUA), and Phenylephrine hydrochloride (PHE) was investigated for spectral resolution and quantification using advanced spectrophotometric methods. The spectra of these components were significantly overlapped and present in their combined tablet in a challenging ratio of 250:100:5 for PAR, GUA, and PHE, respectively. The established approaches were employed for the simultaneous determination of these drugs in their pharmaceutical formulation without interference from matrix excipients. The study involved various manipulation steps, allowing each component in the combination to be analyzed by more than one approach. Integrating these methods with smart mathematical techniques, the issue of spectral data overlap was resolved without the need for preliminary separation steps. The developed methods are dual wavelength, first derivative, derivative ratio, ratio difference, constant center coupled with spectrum subtraction, and constant multiplication paired with spectrum subtraction. The proposed methods were linear over the concentration range of 3.0-35.0 μg/mL for GUA and 3.0-30.0 μg/mL for PHE. While the PAR ranges for the first derivative and constant multiplication methods were 2.5-35.0 μg/mL and 2.5-25.0 μg/mL, respectively. Excellent linearity of the suggested methods was demonstrated by the high correlation coefficients (R2), ≥ 0.9998 for all the tested compounds. These methodologies were validated according to ICH guidelines. Validation results demonstrated excellent accuracy, with recovery percentages ranging from 98 to 102 %, and precision, with RSD values less than 2 %. The obtained results were statistically compared with the official ones using F-test, Student's t-test, and one-way ANOVA, revealing no significant differences. The proposed methods are accurate, green, smart, fast, and cost-effective. Their compliance with Green Analytical Chemistry principles was evaluated and compared to a published method using various tools to enable a more holistic evaluation from different perspectives. The promising results revealed that the investigated methods are superior green alternatives for routine analysis of the cited drugs in laboratories with limited resources and without access to expensive instruments.

High-performance liquid chromatographic method for determination of voriconazole in pure and gel formulation

For routine measurement of Voriconazole (VZ) in a pure and gel formulation, a quick and accurate RP-HPLC technique with UV detection (254 nm) was developed. With a flow rate of 1.0 ml/min using a mobile phase that contained acetonitrile and water mixed 50:50, v/v. Internal standard approach was used for quantification. The method shows good linearity (correlation coefficient = 0.9999) with acceptable accuracy, precision and robustness. Three elements were taken into account to measure robustness. Flow rate, mobile phase composition, and pH all have an impact on the response, but only the flow rate which causes a reduction in the concentration of the drug-has a significant impact on the response. Analyst, equipment, and days were taken into consideration for a precision measurement. The analytical procedure had good precision, as seen by the %RSD which is found to be less than 2.0. The proposed method was straightforward, extremely sensitive, exact, and accurate, and it had a retention time of less than 4 minutes, indicating that it is appropriate for daily quality control.

Simultaneous Chromatographic Estimation of Vildagliptin and Dapagliflozin Using Hybrid Principles of White Analytical Chemistry and Analytical Quality by Design

BACKGROUND

The fixed-dose combination of vildagliptin (VDG) and dapagliflozin (DGZ) is used in the treatment of type 2 diabetes mellitus. According to the literature survey, RP-HPLC and HPTLC methods have been reported for routine analysis of VDG and DGZ. These chromatographic methods have been developed using potentially neurotoxic and teratogenic solvents, which are unsafe for human and aquatic animal life and hazardous to the environment. These types of organic solvents shall be replaced or reduced during chromatographic analysis of drugs for the safety of human and aquatic animal life and the protection of the environment. The novel white analytical chemistry (WAC) approach has been introduced, which emphasizes robust, green, user-friendly, economical, and rapid analysis of drug samples.

OBJECTIVE

Hence, the WAC-based RP-HPLC method has been developed for the estimation of VDG and DGZ using lower toxic and economical solvents.

METHOD

The development of the RP-HPLC method includes the implementation of the analytical quality by design approach using principles of design of experiments to reduce organic waste generation and regulatory compliance of analytical method. The central composite design was applied for response surface modeling (RSM) and optimization of the RP-HPLC method. The method validation was carried out according to ICH Q2 (R1) guidelines.

RESULTS

The fixed-dose combinations of VDG and DGZ were assayed, and results were found in compliance with their labeled claim. The published and proposed RP-HPLC methods were assessed for chromatographic analysis of VDG and DGZ using the Red-Green-Blue (RGB) model, AGREE calculator, Eco-Scale Assessment tool, GAPI software, and NEMI standards.

CONCLUSIONS

The proposed method was found to be robust, green, economical, and user-friendly for chromatographic analysis of VDG and DGZ. The proposed method can be an economical and eco-friendly analytical tool in the pharmaceutical industry for quality control and routine analysis of fixed-dose combinations of VDG and DGZ.

HIGHLIGHTS

Hybrid principles of WAC and analytical quality by design to RP-HPLC method for simultaneous estimation of VDG and DGZ in their fixed-dose combinations.

An integrated framework to develop an efficient valid green (EVG) HPLC method for the assessment of antimicrobial pollutants with potential threats to human health in aquatic systems

The persistence of antimicrobial drugs in aquatic environments has raised critical concerns about their possible impact on drinkable water quality and human health. The Nile River is experiencing water pollution owing to increasing discharges of highly contaminated home and industrial effluents and inadequate water management systems. Investigations of the presence of three antimicrobial agents, ciprofloxacin (CIP), sulfamethoxazole (SMZ), and albendazole (ALB), in the Egyptian aquatic system are recommended using a chromatographic method because of their reported existence in the African aquatic environment. In this study, an integrated framework, Efficient Valid Green (EVG), for analytical techniques is proposed and displayed via its radar chart. The EVG framework is achieved through three main pillars: efficiency, validation, and greenness. The proposed EVG-HPLC method was developed and optimized using the AQbD methodology via a face-centered composite (FCC) design by identifying the proper critical method parameters (CMPs) that influence critical quality attributes (CQAs). The method was fully validated according to ICH guidelines, including a factorial robustness study within concentration ranges of 1-100 μg mL-1, 2-100 μg mL-1, and 10-100 μg mL-1 for CIP, SMZ, and ALB, respectively. The proposed method was evaluated in terms of greenness using AGREE (score 0.55) and ComplexGAPI metrics. The optimized chromatographic conditions included a C18 column and a mobile phase of water : acetonitrile : methanol in a ratio of 60 : 19 : 21, v/v/v, respectively, with an aqueous solution of pH 3.5 adjusted with phosphoric acid at a flow rate of 1.57 mL min-1 at 285 nm. The raw water samples collected from Nile River freshwater at different locations were treated using Oasis® PRiME HLB cartridges with satisfactory recoveries for the three analytes (>90%), and the three drugs were detected using the proposed EVG-HPLC method.

Resolving phenylephrine HCl and guaifenesin enantiomers on cellulose-based chiral stationary phases: Separation of four enantiomers on 50-mm column

Chiral high performance liquid chromatographic technique usually employs polysaccharide-based stationary phases in a normal phase mode. This frequently generates large waste of organic solvents. Using shorter columns of 50 mm length as well as a mobile phase with a high water percentage are common approaches for greening this analytical technique. In this context, a new chiral chromatographic technique was developed for simultaneous enantio-separation of phenylephrine HCl and guaifenesin racemates. Four 50 mm cellulose-based columns were experimented to separate the four enantiomers in a reversed phase mode. A face centered design was then employed to optimize the mobile phase acetonitrile% and flow rate on Lux Cellulose-1 (50 × 4.6 mm, 5 μm). The simultaneous resolution of the cited drugs enantiomers was achieved using acetonitrile-water (30:70, by volume), with a flow rate of 0.5 ml min-1 . These optimized chromatographic conditions separate the enantiomers in 7 min running time, generating about 1.0 ml acetonitrile per run. The proposed method was favorably compared with other reported chiral ones in terms of waste volume generated and analysis time required.

Recent Trends in Fast Liquid Chromatography for Pharmaceutical Analysis

Background:

Liquid chromatography is the workhorse of analytical laboratories of pharmaceutical companies for analysis of bulk drug materials, intermediates, drug products, impurities and degradation products. This efficient technique is impeded by its long and tedious analysis procedures. Continuous efforts of scientists to reduce the analysis time resulted in the development of three different approaches namely, HTLC, chromatography using monolithic columns and UHPLC.

Methods:

Modern column technology and advances in chromatographic stationary phase including silica-based monolithic columns and reduction in particle and column size (UHPLC) have not only revolutionized the separation power of chromatographic analysis but also have remarkably reduced the analysis time. Automated ultra high-performance chromatographic systems equipped with state-ofthe- art software and detection systems have now spawned a new field of analysis, termed as Fast Liquid Chromatography (FLC). The chromatographic approaches that can be included in FLC are hightemperature liquid chromatography, chromatography using monolithic column, and ultrahigh performance liquid chromatography.

Results:

This review summarizes the progress of FLC in pharmaceutical analysis during the period from year 2008 to 2017 focusing on detecting pharmaceutical drugs in various matrices, characterizing active compounds of natural products, and drug metabolites. High temperature, change in the mobile phase, use of monolithic columns, new non-porous, semi-porous and fully porous reduced particle size of/less than 3μm packed columns technology with high-pressure pumps have been extensively studied and successively applied to real samples. These factors revolutionized the fast high-performance separations.

Conclusion:

Taking into account the recent development in fast liquid chromatography approaches, future trends can be clearly predicated. UHPLC must be the most popular approach followed by the use of monolithic columns. Use of high temperatures during analysis is not a feasible approach especially for pharmaceutical analysis due to thermosensitive nature of analytes.

Green chromatographic method for analysis of some anti-cough drugs and their toxic impurities with comparison to conventional methods

Toxic solvents are widely used in chemical laboratories, which are dangerous on health, safety of workers, and environment. Green chemistry established different principles to keep safety of environment, one of these goals is to replace toxic solvents by greener alternatives or by minimizing the used volumes. Paracetamol (PAR), Guaifenesin (GUF), Oxomemazine (OX), and Sodium benzoate (SB) combination is a widely used cough preparation. 4- aminophenol (4-AP) is PAR poisonous impurity and related substance. Guiacol (GUC) is GUF impurity and related substance; its presence may lead to rejection of GUF sample. An eco-friendly HPTLC method was developed to quantify the studied drugs and their impurities. Chromatographic separation was achieved on HPTLC 60F254 plates using ethylacetate: methanol: 0.05 M ammonium chloride buffer (100: 2: 5, by volume) as a mobile phase and scanning at 225 nm. The linear ranges were 0.25-3.50, 0.50-8.00, 0.25-4.00, 0.20-8.00, 0.05-4.00, and 0.25-4.00 µg/band for PAR, GUF, OX and SB, 4-AP, and GUC. Method was successfully applied to available syrup and suppositories. It compared well with the reported method. It can be considered as an alternative green method for previously developed TLC method. Greenness profile of the method proved that it is greener than the reported methods being time and solvents saving.

Response surface design as a powerful tool for the development of environmentally benign HPLC methods for the determination of two antihypertensive combinations: Greenness assessment by two green analytical chemistry evaluation tools

Interest in implementing green chemistry principles in analytical chemistry has grown dramatically in the past few years. The solvents used have the major influence on the greenness of the method. Most conventional high-performance liquid chromatography methods employed utilize solvents that are "hazardous for the environment". In the present study, two-factor three-level response surface design was exploited to develop eco-friendly chromatographic methods for two different mixtures. The first one was atorvastatin and amlodipine and the second one was amlodipine, perindopril, and indapamide. As it is nontoxic to the environment, ethanol was used as the organic modifier in the mobile phase. The separation of the first mixture was attained using phosphate buffer (pH 7)/ethanol (42:58 v/v), and the second mixture was fully resolved using phosphate buffer (pH 5)/ethanol (40:60 v/v). The use of high-performance liquid chromatography allows excellent resolution in a short run time, hence, less waste was produced. The greenness of the developed methods was assessed by two evaluation tools, namely, National Environmental Methods Index and analytical eco-scale, and found to be excellent green analytical methods. Moreover, the developed methods were compared with other reported methods regarding accuracy and greenness and were found to be perfect alternatives to reported methods for separation and quantification of the mixtures.

Greening Reversed-Phase Liquid Chromatography Methods Using Alternative Solvents for Pharmaceutical Analysis

The greening of analytical methods has gained increasing interest in the field of pharmaceutical analysis to reduce environmental impacts and improve the health safety of analysts. Reversed-phase high-performance liquid chromatography (RP-HPLC) is the most widely used analytical technique involved in pharmaceutical drug development and manufacturing, such as the quality control of bulk drugs and pharmaceutical formulations, as well as the analysis of drugs in biological samples. However, RP-HPLC methods commonly use large amounts of organic solvents and generate high quantities of waste to be disposed, leading to some issues in terms of ecological impact and operator safety. In this context, greening HPLC methods is becoming highly desirable. One strategy to reduce the impact of hazardous solvents is to replace classically used organic solvents (i.e., acetonitrile and methanol) with greener ones. So far, ethanol has been the most often used alternative organic solvent. Others strategies have followed, such as the use of totally aqueous mobile phases, micellar liquid chromatography, and ionic liquids. These approaches have been well developed, as they do not require equipment investments and are rather economical. This review describes and critically discusses the recent advances in greening RP-HPLC methods dedicated to pharmaceutical analysis based on the use of alternative solvents.