A green TLC densitometric method for the simultaneous detection and quantification of naphazoline HCl, pheniramine maleate along with three official impurities

Simultaneous measurement of duloxetine hydrochloride and avanafil at dual-wavelength using novel ecologically friendly TLC-densitometric method: application to synthetic mixture and spiked human plasma with evaluation of greenness and blueness

The simultaneous assay of duloxetine hydrochloride (DLX) and avanafil (AVN) in their pure forms, synthetic mixtures, and spiked human plasma was achieved using a novel, eco-friendly, sensitive, and specific HPTLC methodology that have been established and validated. Measuring the levels of co-administered antidepressants and sexual stimulants in biological fluids is an important step for individuals with depression and sexual problems. Separation was performed successfully using pre-coated silica gel 60-F254 as a stationary phase and a mobile phase composed of methanol, acetone, and 33% ammonia (8:2:0.05, v/v/v). Compact bands were produced by the optimized mobile phase that was chosen for development (Rf values were 0.23 and 0.75 for DLX and AVN, individually) after dual-wavelength detection for DLX and AVN at 232 and 253 nm, respectively. The results of polynomial regression analysis were exceptional (r = 0.9999 for both medicines) over concentration ranges of 5-800 and 10-800ng/spot for DLX and AVN, respectively. The quantitation limits were 4.69 and 9.53 ng/spot (0.31 and 0.94 µg/mL), whereas the detection limits were 1.55 and 3.15 ng/spot (0.63 and 1.91 µg/mL), for DLX and AVN, respectively. The International Council for Harmonization (ICH) criteria served as the basis for validating the established approach. Moreover, the proposed technique was evaluated in terms of greenness using four contemporary ecological metrics: The Analytical Greenness software (AGREE), the Green Analytical Procedure Index (GAPI), Eco-Scale, and the National Environmental Method Index (NEMI). Additionally, the Blue Applicability Grade Index (BAGI), a newly developed tool for evaluating the practicality (blueness) of procedures, was taken into consideration when evaluating the sustainability levels of the established approach.

Application of multivariate chemometrics tools for spectrophotometric determination of naphazoline HCl, pheniramine maleate and three official impurities in their eye drops

This work is concerned with exploiting the power of chemometrics in the assay and purity determination of naphazoline HCl (NZ) and pheniramine maleate (PN) in their combined eye drops. Partial least squares (PLS) and artificial neural network (ANN) were the chosen models for that purpose where three selected official impurities, namely; NZ impurity B and PN impurities A and B, were successfully determined. The quantitative determinations of studied components were assessed by percentage recoveries, standard errors of prediction as well as root mean square errors of prediction. The developed models were constructed in the ranges of 5.0-13.0 μg mL-1 for NZ, 10.0-60.0 μg mL-1 for PN, 1.0-5.0 μg mL-1 for NZ impurity B and 2.0-14.0 μg mL-1 for two PN impurities. The proposed models could determine NZ and PN with respective detection limits of 0.447 and 1.750 μg mL-1 for PLS, and 0.494 and 2.093 μg mL-1 for ANN. The two established models were compared favorably with official methods where no significant difference observed.

Green Easily Implemented Spectrophotometric Methods for Concurrent Determination of Ephedrine Hydrochloride and Naphazoline Nitrate in Nasal Preparations Containing Methylparaben

BACKGROUND

Spectrophotometric resolution of a mixture of several drugs is considered a cheaper, simpler, and more versatile alternative compared to costly chromatographic instruments.

OBJECTIVE

The work aims to resolve the interfering spectra of ephedrine hydrochloride, naphazoline nitrate, and methylparaben in nasal preparations using smart spectrophotometric methods.

METHOD

In our work, derivative and dual-wavelength methods were combined to eliminate this interference, under the name of derivative dual-wavelength method. Other methods, namely successive derivative subtraction and chemometric analysis, were also able to eliminate this interference. The methods have proven their applicability as they follow the International Conference on Harmonization (ICH) requirements regarding repeatability, precision, accuracy, selectivity, and linearity. Eco-scale, GAPI, and AGREE tools were used to estimate the possible environmental effects of the methods.

RESULTS

Acceptable results for repeatability, precision, accuracy, selectivity, and linearity were obtained. Limit of detection (LOD) values were 2.2 for ephedrine and 0.3 for naphazoline. The correlation coefficients were above 0.999. The methods were proven to be safe for application.

CONCLUSIONS

The introduced methods are cheap and easily implemented compared to chromatographic techniques. They can be used in purity-checking of raw material and estimation of concentrations in market formulations. The replacement of the published chromatographic techniques with our developed methods is useful when needing to save money, effort, and time.

HIGHLIGHTS

The three components of a decongestant nasal preparation were determined using cheap, green, and versatile spectrophotometric methods that keep the advantages of chromatographic techniques, including accuracy, reproducibility, and selectivity.

Normal-Phase TLC and Gradient Reversed-Phase HPLC for the Simultaneous Determination of Enrofloxacin and Bromhexine HCl in Presence of Two of Their Official Impurities

In this work, two chromatographic methods are developed and validated for the determination of enrofloxacin and bromhexine (BRM) HCl in the presence of two of their specified impurities, ciprofloxacin and BRM impurity C. The suggested chromatographic methods included the use of thin layer chromatography (TLC-densitometry) and high-performance liquid chromatography (HPLC). In case of TLC-densitometry, good separation was achieved by using mobile phase of n.butanol:acetone:water:glacial acetic acid:triethylamine (10:3:1:0.5:0.5, by volume) on silica gel stationary phase at 254-nm detection. The developed HPLC method used BDS HYPERSIL C18 column with a mobile phase of water:acetonitrile:methanol:triflouroacetic acid. A linear gradient elution of 75-10%, 20-50% and 5-40% for water, acetonitrile and methanol, respectively, was applied in 13 min at a flow rate of 1.5 mL min-1. These methods were sufficient to separate the four substances simultaneously, and they are validated as per International Conference on Harmonization guidelines.