Simplified HPLC method for simultaneous determination of erythromycin and tretinoin in topical gel form

Portable smartphone-assisted amperometric immunosensor based on CoCe-layered double hydroxide for rapidly immunosensing erythromycin

Herein, we have manufactured a newly designed bifunctional impedimetric and amperometric immunosensor for rapidly detecting erythromycin (ERY) in complicated environments and food stuffs. For this, bimetallic cobalt/cerium-layered double hydroxide nanosheets (CoCe-LDH NSs), which was derived from Co-based zeolite imidazole framework via the structure conversion, was simultaneously utilized as the bioplatform for anchoring the ERY-targeted antibody and for modifying the gold and screen printed electrode. Basic characterizations revealed that CoCe-LDH NSs was composed of mixed metal valences, enrich redox, and abundant oxygen vacancies, facilitating the adhesion on the electrode, the antibody adsorption, and the electron transfers. The manufactured impedimetric and amperometric immunosensor based on CoCe-LDH has showed the comparable sensing performance, having a wide linear detection range from 1.0 fg mL-1 to 1.0 ng mL-1 with the ultralow detection limit toward ERY. Also, the portable, visualized, and efficient analysis of ERY was then attained at the smartphone-assisted CoCe-LDH-based SPE.

Development and validation of high-performance liquid chromatography method for determination of clarithromycin in pharmaceutical tablets

Clarithromycin is a very important macrolide antibiotic used to treat bacterial infections in human and veterinary medicine. This study reports the development and validation of cost-effective, simple, precise, accurate, and robust high-performance liquid chromatography (HPLC) for the determination of clarithromycin (CLA) in tablets. Reversed-phase chromatography was conducted using a standard column at 55°C with ultraviolet detection at 215 nm. A mobile phase consisting of acetonitrile -2-methyl-2-propanol -potassium phosphate buffer was used at a flow rate of 1.0 mL/min. The proposed method displayed good linearity, precision, accuracy, robustness, and specificity. The present HPLC was compared with capillary electrophoresis and bioassay methods and the results indicated that there was no significant difference between these methods. Moreover, the obtained results demonstrated the validity of the isocratic HPLC, which allows reliable quantitation of CLA in pharmaceutical samples. Thus, it can be used as a substitute alternative methodology for the routine quality control of this medicine, in situations where other methods are less accessible in the laboratory.

Development and validation of stability indicating HPLC–PDA method for the simultaneous determination of benzoyl peroxide and tretinoin in topical dosage form

Background

Acne vulgaris is a very dangerous skin disease leads to psychological disorders. Benzoyl peroxide and tretinoin in combination with topical dosage are used to improve the appearance of acne-prone skin. The study aimed to develop and validate an HPLC–PDA method for the simultaneous estimation of both drugs. Intentional modifications were implemented in the analytical method to get better optimum conditions. The final method was chosen for the reverse phase chromatographic separation by using the C18 column as a stationary phase and 0.01 M phosphate buffer adjusted pH 2.5 mixed with acetonitrile (25:75 v/v) as a mobile phase. The optimized conditions were 1.5 mL/min flow rate, 30 °C column temperature, 5 °C autosampler temperature, and 20 µL injection volume. The wavelength was chosen for detection of Benzoyl peroxide at 272 nm and Tretinoin at 353 nm by utilizing a PDA detector. All standard and sample solutions were made in methanol.

Results

The developed method exhibited peak retention times of 2.94 min for Benzoyl peroxide and 11.34 min for Tretinoin. This analytical method was proven to be robust, linear in calibration curve, accurate, precise, and specific. The forced degradation studies results showed that a high degree of specificity was obtained by separating both analytes from produced impurities completely.

Conclusions

The developed analytical method is fast, economic and stability indicating. It is useful for routine pharmaceutical analysis where the combination of benzoyl peroxide and tretinoin is formulated for their quality and safety.

Application of LTA zeolite-modified electrode for sensitive detection of retinoic acid in tap water

An electrochemical method based on a Linde Type-A zeolite-modified glass carbon electrode (LTA/GCE) was introduced for the determination of retinoic acid (RA). LTA zeolite could be synthesized through a hydrothermal method and served as a commercial electrochemical sensor with high stability and sensitivity in electrochemical progress. The as-synthesized product was characterized by scanning electron microscopy (SEM), differential thermal analysis (DTA), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Under optimal conditions, a detection limit of 0.8 μM was obtained for RA with a linear range of 0.8-20.1 μM. This electrochemical method for determining RA was simpler and cheaper than previously reported methods. Furthermore, the modified electrode could be applied to the detection of RA in tap water, achieving a linear range of 1.4-15.0 μM with a detection limit of 1.4 μM and good recovery. The modified electrode designed by this method provided good selectivity, stability, and reproducibility for RA determination and reliable application for the analysis of RA in environmental water.

Nano-Architectonics of Antibiotic-Loaded Polymer Particles as Vehicles for Active Molecules

Recently, nanotechnology research studies have been proven that use of various nanoparticles as drug delivery systems to target and to annihilate pathogenic microorganisms may be a good solution for prevention and treatment of severe infection. In the last few years, antimicrobial drug encapsulation into nano-sized systems has materialized as a promising alternative that increased drug efficacy and minimized adverse effects. Physicochemical properties of erythromycin-loaded polymer nanoparticles were assessed using particle size distribution, HPLC, FTIR, TG/DTA, and SEM characterization techniques. The as-prepared samples exhibited an average particle size of 340 and 270 nm, respectively, with erythromycin content of 99.7% in both samples. From the release profile of erythromycin from PLA/PLGA, a prolonged drug release can be observed from both Ery-PLA and Ery-PLGA nanostructures. Morphology images exhibited spherical, rigid, and ring-shaped nanoparticles. Thermal analytical study in the case of Ery-PLA and Ery-PLGA samples showed that pure drug has an endothermic peak at around 150 °C assigned to a melting point. The antibiotic melting peak disappeared for both antibiotic-loaded PLA and PLGA nanoparticles thermographs, denoting the presence of erythromycin. This indicates that the antibiotic is uniformly dispensed throughout the host polymer matrix at nanometer scale. FTIR spectra of Ery-PLA and Ery-PLGA nano-architectures with almost similar peaks indicated no alteration in chemical structure of drug-loaded polymer nanoparticles.