Ionic liquids as mobile phase additives for feasible assay of naphazoline in pharmaceutical formulation by HPTLC-UV-densitometric method

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

Impurity profiling of a pharmaceutical compound is now taking great attention during quality assessment of pharmaceuticals, as presence of small amount of impurities may affect safety and efficacy. In this work, a novel TLC chromatographic method coupled with densitometric detection was established for the simultaneous quantification of naphazoline HCl, pheniramine maleate and three of their official impurities, namely; naphazoline impurity B, pheniramine impurities; A & B. Chromatographic separation was carried out on TLC aluminum silica plates F254, as a stationary phase, using methanol: ethyl acetate: 33.0% ammonia (2.0: 8.0: 1.0, by volume), as a mobile phase. Plates were examined at 260.0 nm and International Council for Harmonisation (ICH) guidelines were followed for method's validation. Important factors, such as; composition of mobile phase and detection wavelengths were optimized. Linearity was achieved over the ranges of 2.0-50.0 µg band-1 for naphazoline, 10.0-110.0 µg band-1 for pheniramine, 0.1-10.0 µg band-1 for naphazoline impurity B and 2.0-50.0 µg band-1 for both pheniramine impurities. The proposed method was assessed in terms of accuracy, precision and robustness where satisfactory results (recovery % ≈ 100% and RSD < 2) were obtained. The method was also applied for the simultaneous determination of naphazoline HCl and pheniramine maleate, in Naphcon-A® eye drops, with respective recoveries of 101.36% and 100.94%. Method greenness was evaluated and compared to the reported HPLC one via environmental, health and safety tool. The developed method has much potential over the reported one of being simple, selective, economic and time saving for the analysis of the five cited compounds.

Determination of naphazoline HCl, pheniramine maleate and their official impurities in eye drops and biological fluid rabbit aqueous humor by a validated LC-DAD method

A simple RP-HPLC-DAD method was developed and validated, as per the ICH guidelines, for simultaneous determination of naphazoline HCl (NPZ) & pheniramine maleate (PHN) along with three of their official impurities. Chromatographic separation was performed on a hypersil ODS column (5 mm, 250-4.6 mm i.d.) with isocratic elution using phosphate buffer pH 6.0: acetonitrile (70 : 30, v/v) as mobile phase, at a flow rate of 1.0 mL min-1 and UV detection at 260.0 nm. The developed method was found to be linear over the concentration ranges of 5.00-45.00 μg mL-1 for NPZ and NPZ impurity B and 10.00-110.00 μg mL-1, 10-70 μg mL-1 and 10-120 μg mL-1 for PHN, and PHN impurity A and B, respectively, with correlation coefficient values <0.999 for the five cited compounds. The method was confirmed to be accurate, robust and precise with RSD >2.0%. LOD and LOQ values for the five cited compounds were calculated. Moreover, the method was also validated in rabbit aqueous humor as per the US food and drug administration (FDA) bioanalytical validation guidelines. Finally, the proposed method was applied for the analysis of the two drugs along with their impurities in dosage form and spiked aqueous humor samples.

The Influence of Ionic Liquids on the Effectiveness of Analytical Methods Used in the Monitoring of Human and Veterinary Pharmaceuticals in Biological and Environmental Samples-Trends and Perspectives

Recent years have seen the increased utilization of ionic liquids (ILs) in the development and optimization of analytical methods. Their unique and eco-friendly properties and the ability to modify their structure allows them to be useful both at the sample preparation stage and at the separation stage of the analytes. The use of ILs for the analysis of pharmaceuticals seems particularly interesting because of their systematic delivery to the environment. Nowadays, they are commonly detected in many countries at very low concentration levels. However, due to their specific physiological activity, pharmaceuticals are responsible for bioaccumulation and toxic effects in aquatic and terrestrial ecosystems as well as possibly upsetting the body's equilibrium, leading to the dangerous phenomenon of drug resistance. This review will provide a comprehensive summary of the use of ILs in various sample preparation procedures and separation methods for the determination of pharmaceuticals in environmental and biological matrices based on liquid-based chromatography (LC, SFC, TLC), gas chromatography (GC) and electromigration techniques (e.g., capillary electrophoresis (CE)). Moreover, the advantages and disadvantages of ILs, which can appear during extraction and separation, will be presented and attention will be given to the criteria to be followed during the selection of ILs for specific applications.

Ionic Liquid in Thin-Layer Chromatography of Anionic Surfactants: Selective Separation of Sodium Deoxycholate and Identification in Commercial Products

The coupling of a silica static flat phase impregnated with an ionic liquid (1-methylimidazolium chloride) as stationary phase with 2-methyltetrahydrofuran an alternative green solvent of tetrahydrofuran as mobile phase has been very successful for a selective separation of sodium deoxycholate from other commonly used anionic surfactants. The proposed thin-layer chromatographic system is capable to analytically discriminate among the anionic surfactants in relation to their migration behaviour on an ionic liquid loaded silica layer. The surface structure and chemical composition of silica gel G modified by impregnation were examined with the aid of scanning electron microscopy (SEM) and energy dispersive X-ray spectrophotometry (EDX) respectively. Effects of concentration level of 1-methylimidazolium chloride as impregnant and its substitution by other ionic liquids (1,2,3-trimethylimidazolium methyl sulphate, 1-ethyl-3-methylimidazolium tetrafluoroborate) were also studied to decide the optimum experimental conditions for better separation possibilities. Chromatographic parameters such as ΔRF, the separation factor (α) and the resolution (RS) for the separation and limit of detection were calculated. The developed method has been usefully applied for the identification of sodium deoxycholate and sodium lauryl sulphate in formulated and commercially available products (Colgate toothpaste and Head & Shoulder Shampoo).

Biennial review of planar chromatography: 2011–2013

The most important advances in planar chromatography published between November 1, 2011 and November 1, 2013 are reviewed in this paper. Included are an introduction to the current status of the field; student experiments, books, and reviews; theory and fundamental studies; apparatus and techniques for sample preparation and TLC separations (sample application and plate development with the mobile phase); detection and identification of separated zones (chemical and biological detection, TLC/mass spectrometry, and TLC coupled with other spectrometric methods); techniques and instruments for quantitative analysis; preparative layer chromatography; and thin layer radiochromatography. Numerous applications to a great number of compound types and sample matrices are presented in all sections of the review.