A simple and rapid liquid chromatographic method was developed and validated for the first time for the simultaneous determination of betamethasone valerate (BETA) and clioquinol (CLIO) in creams. Good chromatographic separation was achieved within less than 4 minutes using a Shim-Pack (150 mm  4.6 mm i.d) CLC-cyanopropyl-bonded stationary phase. The mobile phase consisted of a mixture of methanol and 0.02 M phosphate buffer at a ratio of (55 : 45) v/v at pH 4.0 pumped at a flow rate of 1 mL min À1 with UV detection at 240 nm for BETA and 280 nm for CLIO. The method showed good linearity over the concentration ranges of 2-30 and 15-150 mg mL À1 with limits of detection of 0.46 and 2.01 mg mL À1 and limits of quantification of 1.40 and 6.10 mg mL À1 for BETA and CLIO, respectively.The suggested method was successfully applied in the simultaneous analysis of the studied drugs in their commercial creams with mean percentage recoveries of 94.99% AE 0.81 and 95.34% AE 0.60 for BETA and CLIO, respectively. Statistical evaluation of the data was performed according to ICH guidelines.

First derivative synchronous fluorescence spectroscopy (FDSFS) was applied to detect and quantify either ciprofloxacin (CIP) or levofloxacin (LEV) simultaneously with their photodegradation products, where the photolytic pathway for each analyte was found to be pH dependent. Under the guidance of early published articles, the structure of the produced photolytic products could be concluded, and further related to their resultant fluorescence spectra. The proposed method was subjected to full validation procedure which enables its application in investigating the photodegradation kinetics for both drugs. The obtained kinetic parameters were in accordance with previous reports and could be linked to predict the antibacterial activity of the resultant photodegradation products. These facts prove the suitability of the suggested FDSFS to serve as a stability-indicating assay method and to trace the photofate of CIP and LEV in the ecosystem as potential contaminants. Furthermore, the greenness of the suggested analytical methodology was evaluated via ‘Green Analytical Procedure Index’ (GAPI), which classifies it as an eco-friendly assay. Eventually, no extraction, treatment or preparation steps were needed during all analysis steps, which renders the proposed assay an appealing tool in environmental analysis.

A facile, simple, green and sensitive spectrofluorometric method was developed for determination of the calcimimetic drug cinacalcet hydrochloride. It is used for the treatment of hyperparathyroidism. The drug showed high native fluorescence intensity at 320 nm after excitation at 280 nm. The method was linear over the range of 5.0 - 400.0 ng/mL with excellent correlation (R2 = 0.9999). Limit of detection (LOD) and limit of quantitation (LOQ) values were 1.19 and 3.62 ng/mL, respectively. The percentage recovery was found to be 100.42% ± 1.39 (n=8). The proposed method was successfully applied for determination of cinacalcet in spiked human plasma samples with % recoveries of (87.23 to 109.69 %). Two recent greenness metrics (GAPI and Analytical Eco-Scale) were chosen to prove the eco-friendly nature of the method. Furthermore, the proposed method was successfully applied to dissolution study of commercial cinacalcet tablets. The interference likely to be introduced by some commonly co-administrated drugs such as metoprolol and itraconazole was studied; the tolerance limits were calculated. 

A simple, sensitive, and selective first derivative synchronous fluorimetric method was developed and optimized to track the influence of caffeine content in beverages on the pharmacokinetic parameters of three pharmaceuticals used in relieving headache namely, aspirin (ASP), ibuprofen (IBU), and ergotamine tartrate (ERG). A full validation procedure was carried out to impart validity to the proposed method to apply it to biological fluids. The unique dissolving power of micellar solutions was utilized to avoid multiple extraction steps for both the in vitro and in vivo experiments, aiming to obtain acceptable recoveries and to accomplish sustainability, where 0.1 M sodium dodecyl sulphate (SDS) was used for this purpose. Moreover, the developed bioanalytical method was subjected to full validation to avoid interferences emerging from biological matrices. The greenness of the proposed method was assessed according to the Analytical Eco-Scale and proved to be excellent green carrying a score of 98%.