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Author(s): Khadiga M. Kelani [sup.1] [sup.2], Mamdouh R. Rezk [sup.1], Ahmed S. Saad [sup.1] [sup.3], Menna S. ElSherbiny [sup.2], Hany H. Monir [sup.1] Author Affiliations: (1) grid.7776.1, 0000 0004 0639 [...], Two spectrometric methods and a TLC-densitometric method are described for the determination of hyoscine/ketoprofen combination. A new spectrophotometric method called the co-absorptive point has been explained based on the idea of the isosbestic point. This method has been introduced to resolve the overlapped spectra and the challenging drug ratios found in the mentioned dosage form. Also, a dual wavelength technique measuring at 208.4 and 218.2 nm was explained. In the two spectrometric techniques, ketoprofen was determined by zero-order spectra, while hyoscine was determined by co-absorptive point and dual wavelength techniques with linearity ranges of 8-100 and 8-70 [micro]g/mL. In the TLC-densitometric method, the developing phase was methanol-ethyl acetate-ammonia (35 : 65 : 5, v/v) with linearity ranges of 1-20 and 5-25 [micro]g/mL for hyoscine and ketoprofen, respectively. The greenness of the described techniques was assessed according to the eco-scale and compared to previously reported methods.

Substantial preference for target analytes was attained by molecularly-imprinted polymers (MIPs). A novel indirect voltammetric technique was developed to provide a useful gate for the analysis of electro-inactive substances through selective interaction with MIP and hence decrease of redox-active probe signal at the electrode's surface. In this work, a methyldopa-based MIP was fabricated for the selective binding with memantine (MEM), a voltammetry-inactive and widely used drug for Alzheimer's disease. In-situ electropolymerization of methyldopa monomer was implemented onto a pencil graphite electrode using MEM as a template in phosphate buffer pH 7.0. The monomer-template interaction was evaluated by UV-spectroscopy. The modified surface of the electrode was characterized using scanning electron microscope and X-ray photoelectron spectroscopy. The functionality of the sensor was assessed using cyclic voltammetry and electrochemical impedance analysis. The response was linear over a concentration range of 1.0 × 10–12 to 1.0 × 10−10 M with a detection limit down to 1.5 × 10−13 M. Sensor selectivity was studied using the co-formulated drug, donepezil. The MIP-sensor exhibited high sensitivity and proper selectivity, allowing its applicability for the analysis of MEM in combined formulations and in spiked human plasma samples. The overall process was subjected to a greenness and whiteness assessment, confirming its eco-friendliness and sustainability. [ABSTRACT FROM AUTHOR]

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 Green TLC-densitometric determination of antazoline and tetryzoline. Applicability of analysis of studied drugs in eye drops and in rabbit aqueous humor samples. Greenness profile assessment was accomplished via four smart metric tools. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]