Eco-friendly chiral HPLC method for determination of alfuzosin enantiomers and solifenacin in their newly pharmaceutical combination: Method optimization via central composite design

A Novel Spectrofluorimetric Determination of Antazoline and Xylometazoline in their Ophthalmic Formulation; Green Approach and Evaluation

A green developed spectrofluorimetric method has been applied for Antazoline (ANT) and Xylometazoline (XLO) determination in both pharmaceutical formulation and pure form. The developed method is synchronous spectrofluorimetry coupled with the second derivative mathematical tool for the determination of antazoline and xylometazoline in their dosage form. The developed method depends on reacting the cited drugs with dansyl chloride, a suitable derivatizing agent, to generate highly fluorescent derivatives. The products formed were measured at emission wavelengths; 703.0 and 712.0 nm after being excited at wavelengths; 350.0 and 355.0 nm for antazoline and xylometazoline, respectively. Synchronous spectrofluorimetry coupled with second derivative mathematical tool was developed and optimized using fluorescence data manager software generating second derivative peak amplitudes at 556.5 nm for antazoline and 598.0 nm for xylometazoline. Linear responses have been represented over a wide range of concentration 0.5-12.0 µg/mL for antazoline and 0.1-10.0 µg/mL for xylometazoline, correspondingly. Method validation was successfully applied. Additionally, statistical comparison of developed method with official ones has been carried out where no significant difference was found. Evaluation of the method's greenness was proven using several assessment tools. Indeed, the method developed is found to be precise, sensitive, and discriminating to assess the cited drugs for regular analysis.

Development of an HPLC-UV method for quantification of posaconazole in low-volume plasma samples: design of experiments and machine learning models

Posaconazole (PCZ) is a triazole antifungal agent with a broad-spectrum activity. Our research aims to present a novel approach by combining a 2-level fractional factorial design and machine learning to optimize both chromatography and extraction experiments, allowing for the development of a rapid method with a low limit of quantification (LOQ) in low-volume plasma samples. The PCZ retention time at the optimized condition (organic phase 58%, methanol 6%, mobile pH = 7, column temperature: 39 °C, and flow rate of 1.2 mL/min) was found to be 8.2 ± 0.2 min, and the recovery of the PCZ at the optimized extraction condition (500 µL extraction solvent, NaCl 10% w/v, plasma pH = 11, extraction time = 10 min, and centrifuge time = 1 min) was calculated above 98%. The results of machine learning models were in line with the results of experimental design. Method validation was performed according to ICH guideline. The method was linear in the range of 50-2000 ng/mL and LOQ was found to be 50 ng/mL. Additionally, the validated method was applied to analyze PCZ nanomicelles and conduct pharmacokinetic studies on rats. Half-life (t1/2), mean residence time (MRT), and the area under the drug concentration-time curve (AUC) were found to be 7.1 ± 0.6 h, 10.5 ± 0.9 h, and 1725.7 ± 44.1 ng × h/mL, respectively.

A Novel Spectrofluorimetric Method for Vibegron in the Newly FDA Approved Pharmaceutical Formulation and in Human Plasma: Analytical QbD Strategy for Method Development and Optimization

Vibegron is a novel selective beta-3 adrenergic receptor agonist molecule, recently approved by US Food and Drug Administration (FDA) in tablet pharmaceutical formulation for treating overactive bladder syndrome. Such formulation necessitates the development of a simple, fast and cost-effective methodology capable of assaying the drug in various real samples with high sensitivity. Herein, a facile and robust spectrofluorimetric method was introduced, for the first time, for vibegron quantification based on analytical quality-by-design approach. The method involves drug reaction with dansyl chloride at pH 9.8, as a smart approach to overcome the non-fluorescent nature of vibegron, giving a highly fluorescent yellow derivative measured at 514 nm after being excited at 345 nm. Plausible reaction scheme between the drug and dansyl chloride was elucidated through studying the differences in their infrared (IR) spectra. Variables affecting fluorescence intensities were carefully screened and rationally optimized via preliminary scouting studies and central composite design for accurate and robust results. Full International Council for Harmonisation (ICH) validation protocol was followed where linearity was achieved in range of 20.0-400.0 ng/mL with minimum detectability of 3.6 ng/mL. The proposed method expressed good capability in assaying the marketed dosage forms with no excipient inference. Finally, the high sensitivity of such method paved the way for extending its application to quantify vibegron in spiked human plasma at concentrations around its real human plasma concentrations for further bioavailability studies.

Possibilities and limitations of computer assisted chiral HPLC method development for ozanimod on polysaccharide based chiral stationary phases

In this study, a direct HPLC method was developed to determine the enantiomeric purity of the immunomodulatory drug, ozanimod. A systematic method development process was followed, incorporating risk assessment, identification of critical analytical procedure parameters, initial screening of stationary phases, and software-assisted optimization of method parameters. Eight different polysaccharide-based chiral columns were selected to assess chiral separation of enantiomers under polar organic elution mode. The most promising results were obtained using a methanol:2-propanol mixture on the amylose-based Chiralpak AD column. Following this, systematic modeling was conducted using DryLab software to optimize method conditions, including isocratic eluent composition, temperature, and flow rate. Baseline separation was achieved within fifteen minutes using the optimized parameters: Chiralpak AD column thermostated at 10 °C, and a mobile phase of methanol:2-propanol: diethylamine, 70:30:0.1 (v/v/v %), delivered at a flow rate of 0.8 mL/min. The developed method was validated according to current guidelines and in silico robustness testing was conducted to determine tolerance limits for critical separation parameters and their impact on enantioresolution. Our findings demonstrate the utility of DryLab, typically employed for reversed-phase achiral separations, in optimizing chiral methods even in polar organic mode. Limitations of the selected approach the development of chiral separation methods are also highlighted.

Green TLC-Densitometric Method for Simultaneous Determination of Antazoline and Tetryzoline: Application to Pharmaceutical Formulation and Rabbit Aqueous Humor

Ophthalmic pharmaceutical preparation containing antazoline (ANT) and tetryzoline (TET) is prescribed widely as an over the counter medication for allergic conjunctivitis treatment. Development of a selective, simple and environmentally friendly thin-layer chromatographic method established to determine both ANT and TET in their pure forms, pharmaceutical formulation and spiked aqueous humor samples. By using silica gel plates and means of a developing system consists of ethyl acetate:ethanol (5:5, by volume), the studied drugs separation was achieved, and scanning was carried out at 220.0 nm for the separated bands with a 0.2-18.0 μg/band concentration range for each of ANT and TET. Standard addition technique application was carried out to determine the proposed method validity. Statistical comparison was made between the proposed method and the official methods ANT and TET showing no significant difference concerning accuracy and precision. Furthermore, greenness profile assessment was accomplished by means of four metric tools, namely, analytical greenness, green analytical procedure index, analytical eco-scale and national environmental method index.

Highlights.

Eco-Friendly Simultaneous Estimation of Ponceau 4R and Carmoisine Employing an Analytical Quality by Design-Aided RP-HPLC Method in Commercial Food Samples Utilizing a Green Ultrasound-Assisted Extraction Technique

BACKGROUND

Ponceau 4R (E124) and carmoisine (CMS; E122) are frequently utilized azo synthetic dyes in the food industry owing to their aesthetically pleasing coloration and broad consumer acceptability. It is imperative to prioritize environmentally favorable technologies for quantifying these dyes, as excessive consumption of these poses significant health risks.

OBJECTIVE

The primary objective of this research was to establish a reversed-phase (RP)-HPLC method that could simultaneously detect Ponceau 4R and CMS, implementing green analytical chemistry (GAC) and analytical quality by design (AQbD), using an ultrasound-assisted extraction (UAE) technique in commercial food samples.

METHODS

An Agilent Eclipse Plus column (C18, 250 × 4.6 mm id, 5 µm) was utilized for effective separation with a mobile phase of ethanol-acetate buffer pH 5 (60:40, v/v), flow rate of 1 mL/min, and detection wavelength of 515 nm. Critical variables selected for method optimization were ethanol percentage and flow rate, determined using central composite design (CCD). In order to adhere to the 12 principles of green chemistry, hazardous solvents were substituted with ethanol, which is distinguished by its ease of use, effectiveness, and ecological sustainability. The greenness assessment was conducted utilizing the green analytical procedure index (GAPI), analytical eco-scale (AES), and analytical greenness metrics (AGREE).

RESULTS

The respective retention times for Ponceau 4R and CMS were 2.276 and 3.450 min. The recovery rate of Ponceau 4R and CMS fluctuated between 70% and 102% and 80% and 102%, respectively, across various marketed food samples. The procedure passed validation in accordance with the International Conference on Harmonization Q14 guidelines.

CONCLUSION

The devised method demonstrates that the validation parameters like linearity, precision, sensitivity, and reproducibility are within the specified limits of ICH guidelines. The greenness assesment tools GAPI, AES, and AGREE produced the most favorable results.

HIGHLIGHTS

In future, environmentally sustainable, solvent-based, robust AQbD methodologies for assessing varieties of food colorants may be adopted and improved commercially.

Simultaneous determination of lesinurad and febuxostat in commercial fixed-dose combinations using a greener normal-phase HPTLC method

So far, no documented method for simultaneously analyzing lesinurad (LND) and febuxostat (FBX) has been reported for either traditional high-performance thin-layer chromatography (HPTLC) or a green HPTLC technique. In order to determine LND and FBX simultaneously in commercially available fixed-dose combo tablets, this study devised a normal-phase HPTLC method that is fast, sensitive, and green. The green eluents for the simultaneous analysis of LND and FBX were a mixture of ethyl acetate:ethanol:water at 70:20:10 (v/v/v) ratio. The new approach’s greenness was predicted utilizing four distinct greenness tools: the National Environmental Method Index, Analytical Eco-Scale, ChlorTox, and Analytical GREENness approaches, and the results revealed a significantly greener profile. The current method operated on a linear scale between 30 and 1,000 ng·band−1. It was confirmed that the current approach is sensitive, accurate, precise, robust, and green. The LND and FBX contents of commercially available tablet products A and B were found to be within the range of 100 ± 2%, indicating that the existing methodology for simultaneously determining LND and FBX in pharmaceutical combination products is applicable. The results of the current methodology indicated that LND and FBX could be consistently measured in pharmaceutical combination products simultaneously using the current approach.

A novel green spectrofluorimetric method for simultaneous determination of antazoline and tetryzoline in their ophthalmic formulation

A novel spectrofluorimetric method has been developed for determination of antazoline (ANT) and tetryzoline (TET) in their pharmaceutical formulation. A combined application of synchronous spectrofluorimetry and second derivative mathematical treatment was developed. The proposed method depends on reacting the cited drugs with dansyl chloride (DNS-Cl) being a suitable derivatizing agent generating highly fluorescent derivatives measured at emission wavelengths of 703.0 and 642.0 nm after excitation wavelengths of 350.0 and 320.0 nm for ANT and TET, respectively. The joint use of synchronous spectrofluorimetry with second derivative mathematical treatment is for the first time to be developed and optimized in aid of using fluorescence data manager software generating second derivative peak amplitudes at 556.5 nm for ANT and 516.7 nm for TET. Linear responses have been represented over a wide range of concentration (0.5-12.0 μg/mL for ANT and 0.5-10.0 μg/mL for TET). Additionally, statistical comparison of the developed method with the official ones has been carried out where no significant difference was found. Additionally, greenness profile assessment was accomplished by means of four metric tools. Indeed, the method developed is found to be precise, sensitive, and discriminating to assess the cited drugs for regular analysis.

State-of-the-art mathematically induced filtration approaches for smart spectrophotometric assessment of silodosin and solifenacin mixture in their new challenging formulation: Multi-tool greenness and whiteness evaluation

Benign prostatic hyperplasia is one of the most predominant health disorders in men with increasing incidence by age and usually accompanied with other bothersome symptoms. A new fixed dose combination, containing Silodosin and Solifenacin, has been recently launched for relieving such disorder associated with overactive bladder syndrome. In the current work, three smart, innovative and white spectrophotometric methods have been newly developed and optimized for simultaneous determination of the studied drugs in their binary mixture using water as an eco-friendly solvent. The adopted strategy relied on calculation of one or two factors as numerical constant or spectrum allowing mathematical filtration of desired analyte and full removal of any overlapped components in the mixture. The developed methods are categorized over two spectrophotometric platform windows. Window I deals with absorption spectra in its native forms (zero-order) including a newly developed method termed induced concentration subtraction (ICS) as well as induced dual wavelength (IDW) methods. Whereas window III is concerned with ratio spectra as in induced amplitude modulation (IAM) method. Compared to classical spectrophotometric methods, the proposed ones are superior in overcoming the inherited challenges in zero-order absorption spectrum of Solifenacin, particularly its very low absorptivity and lack of unique absorption maximum. Validity of the methods were thoroughly assured as per ICH guidelines with unified regression over 3.0-50.0 µg/mL in ICS method while IDW and IAM ones possessed linearity ranges of 3.0-50.0 µg/mL of Silodosin and 5.0-60.0 µg/mL of Solifenacin. The work was also extended to verify content uniformity of dosage units in accordance with USP recommendations. Greenness profile of the proposed methods was clearly assessed, in comparison to the reported analysis ones, via state-of-the-art software metrics, namely, green solvent selection tool (GSST), complementary green analytical procedure index (ComplexGAPI) and analytical greenness (AGREE). Finally, the proposed methods were in good adherence to the recently published postulates of white analytical chemistry.

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.

Micellar-enhanced and green-assessed first-derivative synchronous spectrofluorimetric approach for concurrent determination of alfuzosin hydrochloride and solifenacin succinate in different matrices: Docking simulation

Alfuzosin hydrochloride (AZH) is co-formulated with solifenacin succinate (SOS) in Solitral® capsules for treating prostate hyperplasia in patients with overactive bladder syndrome. Herein and for the first time, an ultrasensitive synchronous spectrofluorimetric approach coupled with first-order derivative signal processing was designed for simultaneous determination of AZH and SOS in their pure forms, newly-released pharmaceutical capsules, and human biological fluids. AZH and SOS showed their conventional emission spectra in bi-distilled water at 382 nm and 294 nm after excitation at 325 nm and 250 nm, respectively. The native fluorescence intensities of AZH and SOS were greatly enhanced through micellar formation using sodium dodecyl sulfate surfactant (2%). The proposed approach included the use of synchronous mode at Δλ of 60 nm where the overlap between the studied analytes' fluorescence spectra wasn't completely resolved. The complete resolution was achieved by derivatization of the synchronized spectra to the first-order yielding two zero-crossing points which allowed the determination of AZH and SOS simultaneously without interference at 408 nm and 321 nm, respectively. Under optimum experimental circumstances, good linearities were accomplished over the concentration ranges of (1-24) ng/mL and (4-250) ng/mL with LOD of 0.26 ng/mL and 1.31 ng/mL for AZH and SOS, respectively. The proposed approach was validated successfully according to guidelines adopted by the ICH and compared statistically with the reported LC method with no discernible differences concerning accuracy or precision at p = 0.05. Successful application of the proposed approach achieved with excellent recovery percentages for analysis of the studied analytes in different matrices (pharmaceutical capsules and biological fluids) confirms its suitability for use in QC laboratories and other bioanalytical applications. The proposed approach's greenness was evaluated using two tools namely; penalty points scoring system and green analytical procedure index (GAPI) divulging excellent greenness of this approach relative to the reported LC method. The proposed approach relied chiefly on water as the cheapest and greenest solvent.

A novel smartphone HPTLC assaying platform versus traditional densitometric method for simultaneous quantification of alfuzosin and solifenacin in their dosage forms as well as monitoring content uniformity and drug residues on the manufacturing equipment

The large popularity and rapid technology of smartphones have opened new avenues for their integration into different analytical methodologies and drug quality monitoring as a portable, easily accessible, and user-friendly detector. Herein, a novel and portable smartphone-based high-performance thin layer chromatographic (HPTLC) approach is proposed for the simultaneous analysis of two urological drugs, alfuzosin and solifenacin, which treat benign prostatic hyperplasia accompanied by overactive bladder syndrome. First, chromatographic separation was accomplished using an ecofriendly mobile phase, then the developed plates were visualized using Dragendorff's reagent and photographed via a smartphone's rear-facing camera fixed on a fabricated two-illumination-source chamber. The intensities of the drug spots were quantified using open-source image analysis software ImageJ over the concentration ranges of 2.0 to 30.0 μg per band for both drugs with acceptable results in ICH validation parameters. To improve the method's accuracy and reproducibility, various construction and shooting key parameters were investigated and optimized. Moreover, the study was extended to compare the obtained results with those of a benchtop densitometric method using a Camag TLC Scanner 3 at 215.0 nm; the densitometric method provided an additional assessment tool for peak purity and was capable of assaying lower drug concentrations over a linearity range of 0.2-8.0 μg per band for alfuzosin and 0.1-6.0 μg per band for solifenacin. The fast, simple, reliable, green merits of the proposed HPTLC/smartphone method suggest that it is an excellent platform for assaying marketed combined capsules and assuring their content uniformity. Moreover, the high sensitivity of the densitometric method was used, for the first time, to determine the residual content of the cited drugs on manufacturing equipment surfaces for cleaning validation. Finally, the environmental impact of the developed methods was evaluated based on green analytical chemistry principles.

Novel sensing probe using Terbium-sensitized luminescence and 8-hydroxyquinoline for determination of prucalopride succinate: green assessment with Complex-GAPI and analytical Eco-Scale

A highly sensitive spectrofluorimetric method is developed for the determination of prucalopride succinate (PRU). The method depends on lanthanide-sensitized luminescence due to complex formation between the drug and terbium chloride (Tb⁺³) which is enhanced by the addition of 8 hydroxyquinoline (8HQ) and phosphate buffer (0.02 M, pH 3.2). The calibration curve was constructed over the linear range 10–300 ng/mL after excitation at 226 nm and measuring the emission of the ternary complex at 544 nm. The method was validated according to ICH Q2 (R1) guidelines and showed a good recovery ± RSD of 100.41% ± 1.26, the limits of detection and quantitation were found to be 2.81 and 8.53 ng/mL, respectively. The proposed method was successfully applied for the determination of the drug marketed tablet dosage form and the results were in good agreement with the reference method. Also, the method greenness was evaluated according to Complex-GAPI and analytical Eco-Scale.

Two Validated Chromatographic Methods for Determination of Ciprofloxacin HCl, One of its Specified Impurities and Fluocinolone Acetonide in Newly Approved Otic Solution

Two sensitive, selective and precise chromatographic methods have been established for concomitant quantification of ciprofloxacin HCl (CIP), fluocinolone acetonide (FLU) along with ciprofloxacin impurity A (CIP-imp A). The first method was thin-layer chromatography (TLC-densitometry) where separation was accomplished using TLC silica plates 60 G.F254 as a stationary phase and chloroform-methanol-33%ammonia (4.6:4.4:1, by volume) as a developing system. The obtained plates were scanned at 260 nm over concentration ranges of 1.0-40.0, 0.6-20.0 and 1.0-40.0 μg band-1 for CIP, FLU and CIP-imp A, respectively. The second method was based on high-performance liquid chromatography using a Zorbax ODS column (5 μm, 150 × 4.6 mm i.d.) where adequate separation was achieved through a mobile phase composed of phosphate buffer pH 3.6-acetonitrile (45:55, v/v) at flow rate 1.0 mL min-1 with ultraviolet detection at 254 nm. Linear regressions were obtained in the range of 1.0-40.0 μg mL-1 for CIP, 0.6-20.0 μg mL-1 for FLU and 1.0-40.0 μg mL-1 for CIP-imp A. The suggested methods were validated in compliance with the International Conference on Harmonization guidelines and were successfully applied for determination of CIP and FLU in bulk powder and newly marketed otic solution.

Fingerprinting and iso-absorptive resolution techniques for the spectrally overlapping Dutasteride and Silodosin mixture: Content uniformity testing along with greenness profile assessment

The realm of spectrophotometric analysis has witnessed a remarkable progress in inventing faster and simpler resolution techniques for spectrally overlapping drug mixtures. Eco-friendly and progressive spectrophotometric methods were firstly developed in this work, for the simultaneous determination of Dutasteride (DUT) and Silodosin (SLD) in their newly-marketed dosage form. The proposed methods focused on the unique spectral features of this mixture including spectral extension of SLD over DUT spectrum as well as existence of iso-absorptive points. By such way, the methods were classified into two categories; the first one was "fingerprint resolution techniques" including constant extraction coupled with spectrum subtraction and ratio subtraction coupled with constant multiplication methods. The former represented a new modification to the classical constant extraction method where one divisor and lower steps were manipulated instead. The second category was "iso-absorptive resolution techniques", such as absorptivity centering, absorbance subtraction and amplitude modulation methods. Different solvents were investigated where ethanol was found to be the optimum one regarding drugs solubility, signal sensitivity and environmental, health & safety (EHS) score. Validity of the suggested methods was assessed as per ICH-guidelines and found to be linear over concentration ranges of 5.0-90.0 µg/mL for DUT and 5.0-120.0 µg/mL for SLD. The methods were successfully applied for quantifying the cited drugs in their combined dosage form and evaluating their content uniformity. Moreover, the insignificant statistical difference between the proposed methods and official HPLC ones encourages the utilization of such spectrophotometric methods as greener and faster candidates, especially in modest quality control laboratories. Methods' greenness profile was finally guaranteed through several assessment tools, namely; national environmental methods index (NEMI), analytical eco-scale, green analytical procedure index (GAPI) and analytical greenness (AGREE) metric.

Surface blocking of azolla modified copper electrode for trace determination of phthalic acid esters as the molecular barricades by differential pulse voltammetry: response surface modelling optimized biosensor

In this work, a sensitive and efficient voltammetric biosensor was introduced for differential pulse voltammetric (DPV) determination of dibutyl phthalate, dimethyl phthalate, di(2-ethylhexyl)phthalate and dicyclohexyl phthalate in aqueous solutions.