Developing an analytical method by HPLC for simultaneous quantification of methylene blue and metformin applied to in vitro skin permeation and retention studies

Abstract

The aim of this study was to develop an HPLC method for simultaneous quantification of metformin (MET) and methylene blue (MB) in in vitro skin permeation/retention studies, in which retention was evaluated in the different layers of the skin [stratum corneum (SC) and the viable epidermis + dermis (VE + D)]. The method was validated considering the following parameters: specificity, linearity, quantitation limit (LOQ), recovery, precision and accuracy. Calibration curves were obtained using the following six matrices: methanol, water, methanolic extracts from the SC and VE + D spiked with the drugs and drugs extracted from the SC and VE + D. The precision, accuracy and LOQ of the method were evaluated in water and in VE + D and SC, applying the drug extraction process. The results show that the method is selective and linear for both drugs. The precision and accuracy values, independent of matrix and drug, were below the limit of 15%. The LOQ of MB was defined as 0.4 μg/ml in the VE + D and SC and 0.8 μg/ml in water. The LOQ of MET was defined as 0.8 μg/ml in the VE + D and SC and 0.4 μg/ml in the water. The recovery of the method was adequate, consistent and reproducible for the concentration range of 0.4-10 μg/ml for MB (73.3-92.1%) and 0.8-10.0 μg/mL for . This method has a potential application in the development of formulation for skin delivery of MB and MET.

Green synthesized Ag/rGO embedded flexible cotton SERS substrate for detection of methylene blue

“…For humans, intake of MB beyond permissible limits causes several health issues such as abdominal disorders, blindness, respiratory distress, mental disorder, and digestive disorder (Abdelrahman et al 2020). Various sensitive and reliable techniques such as liquid chromatography (LC) (Turnipseed et al 2020), high-performance liquid chromatography-mass spectroscopy (HPLC-MS) ( Matos et al 2021), resonance light scattering (RLS) (Fan et al 2017), and liquid chromatography-tandem mass spectroscopy (LC-MS/MS) (Tarbin et al 2008) are used to detect MB residues. However, these standard techniques are expensive, complex, consume time and labor (Khajuria et al 2016).…”