Development and validation of a UPLC method for the determination of duloxetine hydrochloride residues on pharmaceutical manufacturing equipment surfaces

A novel smartphone HPTLC assaying platform versus traditional densitometric method for simultaneous quantification of alfuzosin and solifenacin in their dosage forms as well as monitoring content uniformity and drug residues on the manufacturing equipment

The large popularity and rapid technology of smartphones have opened new avenues for their integration into different analytical methodologies and drug quality monitoring as a portable, easily accessible, and user-friendly detector. Herein, a novel and portable smartphone-based high-performance thin layer chromatographic (HPTLC) approach is proposed for the simultaneous analysis of two urological drugs, alfuzosin and solifenacin, which treat benign prostatic hyperplasia accompanied by overactive bladder syndrome. First, chromatographic separation was accomplished using an ecofriendly mobile phase, then the developed plates were visualized using Dragendorff's reagent and photographed via a smartphone's rear-facing camera fixed on a fabricated two-illumination-source chamber. The intensities of the drug spots were quantified using open-source image analysis software ImageJ over the concentration ranges of 2.0 to 30.0 μg per band for both drugs with acceptable results in ICH validation parameters. To improve the method's accuracy and reproducibility, various construction and shooting key parameters were investigated and optimized. Moreover, the study was extended to compare the obtained results with those of a benchtop densitometric method using a Camag TLC Scanner 3 at 215.0 nm; the densitometric method provided an additional assessment tool for peak purity and was capable of assaying lower drug concentrations over a linearity range of 0.2-8.0 μg per band for alfuzosin and 0.1-6.0 μg per band for solifenacin. The fast, simple, reliable, green merits of the proposed HPTLC/smartphone method suggest that it is an excellent platform for assaying marketed combined capsules and assuring their content uniformity. Moreover, the high sensitivity of the densitometric method was used, for the first time, to determine the residual content of the cited drugs on manufacturing equipment surfaces for cleaning validation. Finally, the environmental impact of the developed methods was evaluated based on green analytical chemistry principles.

A Validated UPLC-PDA Method for Simultaneous Determination of 3 Biologically Active Isoflavans in Trigonella stellata Extract

In this study, an ultra-performance liquid chromatography (UPLC)/photodiode array method was developed for the simultaneous determination of trigonellan glucoside (1), isotrigonellan (2), and methoxy-isotrigonellan (3) in Trigonella stellata extract using an external standard method. The extract was prepared using a standardized method by maceration of the dried plant material in ethanol. The 3 isoflavans (1-3) were separated on an Acquity UPLC C18 column using gradient elution with a mobile phase consisting of 0.1% (v/v) formic acid aqueous solution and 0.1% (v/v) formic acid in acetonitrile, and ultraviolet detection. The method provides a linear correlation for all analytes over the investigated ranges with all correlation coefficients greater than 0.998. The validated lower limits of quantitation were 53, 127, and 5 μg/mL for isoflavans 1, 2, and 3, respectively. Intraday and interday precisions (percent relative SD [RSD%]) were less than 8.3% and accuracy (RE%) ranged from 90% to 100%. The method’s capability to remain unaffected by small, but deliberate variations in method parameters (method’s reliability during normal usage) described by the robustness showed RSD% less than 4.6% measured by varying 3 different parameters. The validated method was successfully applied to simultaneously determine the concentration of the 3 new isoflavans having anti-inflammatory and antidiabetic activities. The results revealed that the validated method can be used for quality control of herbal preparations containing these or similar isoflavans that are marketed for the prevention of inflammation and as antidiabetics.

Toward Flexible Surface-Enhanced Raman Scattering (SERS) Sensors for Point-of-Care Diagnostics

Surface-enhanced Raman scattering (SERS) spectroscopy provides a noninvasive and highly sensitive route for fingerprint and label-free detection of a wide range of molecules. Recently, flexible SERS has attracted increasingly tremendous research interest due to its unique advantages compared to rigid substrate-based SERS. Here, the latest advances in flexible substrate-based SERS diagnostic devices are investigated in-depth. First, the intriguing prospect of point-of-care diagnostics is briefly described, followed by an introduction to the cutting-edge SERS technique. Then, the focus is moved from conventional rigid substrate-based SERS to the emerging flexible SERS technique. The main part of this report highlights the recent three categories of flexible SERS substrates, including actively tunable SERS, swab-sampling strategy, and the in situ SERS detection approach. Furthermore, other promising means of flexible SERS are also introduced. The flexible SERS substrates with low-cost, batch-fabrication, and easy-to-operate characteristics can be integrated into portable Raman spectroscopes for point-of-care diagnostics, which are conceivable to penetrate global markets and households as next-generation wearable sensors in the near future.