Current Spectroscopy and Chromatography - Current Issue

Software has been used to predict metabolic pathways for possible ‘expected’ and ‘unexpected’ metabolites based on their m/z and fragmentation patterns from low- and high-fragmentation mass spectra of plants subjected to carbamazepine uptake has been used.

Three plants with high prevalence in the natural protected area of Doñana National Park (Spain) were irrigated with three aqueous carbamazepine solutions (10 ng‧mL^-1, 700 ng‧mL,^-1 and 10 μg‧mL^-1). Periodically, stems, leaves, and roots were sampled and analyzed. Total carbamazepine uptake throughout the assay was evaluated and discussed, demonstrating a clear dependence on plant species/part, irrigation solution concentration, and assay duration. Additionally, chromatographic analysis was performed using a quadrupole time-of-flight (Q-TOF) mass spectrometer, recording simultaneous low and high-fragmentation mass spectra for further computational processing with Metabolynx^TM software.

Confirmation was achieved by analyzing the high-energy spectra obtained at the characteristic retention times and fragmentation pattern of each compound.

Several potential carbamazepine metabolites corresponding to various metabolic pathways were identified, and, where possible, their relative abundances was discussed.

The use of computational tools like Metabolynx^TM has proven to be useful for studies involving the identification of metabolites and/or the confirmation of metabolic pathways in the studied plants.

Geographical location plays a crucial role in the distribution and potency of medicinal plants. Chemical composition of plants and their medicinal properties can be significantly influenced by climate and soil composition. The present objective is to investigate the manifestation in phytocompounds of Rubia cordifolia L. root originating from different biogeographical locations in the Indian subcontinent. R. cordifolia is traditionally used to treat chronic pyrexia and puerperal fever, along with reducing the heat and itching in various skin diseases. Other therapeutic benefits include immune-modulatory, analgesic, diuretic, hepatoprotective, nephroprotective, gastroprotective, wound-healing, and antiviral properties.

This study establishes a qualitative profile and analyzes the amount of rubiadin in the root of Rubia cordifolia L. across four different biogeographical zones by using a reproducible and validated HPTLC method.

The study revealed phytochemical arrays are not identical for plants of different zones and that the quantity of rubiadin was highest (0.73%) and lowest (0.27%) in the plants grown in the Deccan Plateau region and northeast region, respectively.

The study demonstrates that the Indian subcontinent boasts a rich tapestry of biodiversity, and this diversity is reflected in the array of phytocompounds found across its various biogeographical regions, mainly due to climate and soil characteristics.

This information can be valuable for applications in agriculture, pharmaceuticals, and environmental studies because understanding the distribution and concentration of phytocompounds across different locations can have numerous applications in these fields.

Reverse-phase high-performance liquid chromatography is a simple, quick, accurate, sensitive, and reproducible technique for quantitatively analyzing Tadalafil and Macitentan in pharmaceutical dosage form. This method is novel as it allows for the simultaneous quantification of both Tadalafil and Macitentan in a single run, which is not widely reported in existing literature.

Waters Alliance-e2695 was used to perform the chromatographic separation of Tadalafil and Macitentan using an Agilent Eclipse XDB C18 (150 x 4.6 mm, 3.5 µ) column and a mobile phase that contained acetonitrile: 0.1% TFA in a 50:50% v/v ratio. At room temperature, the flow rate was found to be 1.0 ml/min, and a photodiode array detector was used to monitor the absorption at 301 nm.

For Tadalafil and Macitentan, the theoretical plate count was not less than 2000, and the tailing factor should not exceed 2. All measurements have a percentage relative standard deviation of peak areas that is consistently smaller than 2.

The suggested approach was validated in compliance with ICH Q2 (R1) regulations. This method was deemed simple, cost-effective, accurate, precise, and reliable for quantitative analysis of the stability study of Tadalafil and Macitentan. The novelty of this work mainly depends on the use of specific mobile phase composition, pH, column type, or detection wavelength that achieves excellent separation and peak resolution within a shorter run time.

This study shows excellent sensitivity with low LOD/LOQ values, and superior efficiency through rapid analysis, good resolution, and robustness, making it suitable for routine quality control and pharmaceutical analysis.

Loperamide is a widely produced generic medication included in the WHO list of essential medicines. Analysing trace amounts of the drug on the surfaces of equipment and in industrial cleaning rinse waters is crucial in pharmaceutical manufacturing. This paper presents a method for measuring loperamide hydrochloride in industrial equipment rinse waters using multiwavelength derivative UV spectrophotometry and the calculation of areas under the curves.

Spectra were obtained in an aqueous solution without prior adjustments to the pH. The spectra were numerically integrated over the wavelength range of 218 to 238 nm. The quantification of loperamide is conducted through the use of a regression equation.

The technique allows for the measurement of loperamide hydrochloride in solution within the concentration range of 1-60 mg/L, with a limit of detection of 1.9 mg/L and a limit of quantification of 5.8 mg/L. The relative uncertainties are not greater than 3% for the analysis of solutions from active pharmaceutical ingredients and not greater than 7% for the analysis of model rinse waters. The relative standard deviations are up to 3% for solutions from active pharmaceutical ingredients and up to 7% for model rinse waters.

The analytical performance of the method is comparable to existing methods of spectrophotometric analysis of loperamide. The advantages of this method are that it requires minimal sample preparation, does not use toxic organic solvents, and does not involve complex analytical instrumentation, making it suitable for the routine analysis of loperamide in rinse waters from industrial equipment cleaning.

The spectrophotometric method of determination of loperamide hydrochloride in aqueous medium using the derivative spectroscopy and the area under the curve method is proposed for the analysis of the rinse waters from industrial equipment cleaning.

A combination of serdexmethylphenidate and dexmethylphenidate are used to treat attention deficiency hyperactivity disorder. A stability-indicating RP-HPLC method has been developed and reported in the literature. As there is no study on the degradation product identification, in this work, the degradation behavior of serdexmethylphenidate and dexmethylphenidate was explored by subjecting combined dosage to the forced degradation study by applying the developed RP-HPLC method. Further, plausible structures and fragmentation patterns of all the degradation products were identified by the LC-MS/MS study.

The forced degradation study was conducted by exposing the combined dosage form (Azstarys) as per International Council of Harmonization (ICH) guideline Q1A (R2). Using LC-MS/MS, MS spectra were obtained. Based on the m/z values and molecular formula, probable structures of degradation products were elucidated.

A total of 7 degradation products were detected, of which, 4 degradation products were formed from serdexmethylphenidate. The remaining 3 degradation products were formed from dexmethylphenidate. The possible structures and fragmentation patterns of all the degradation products were examined with the help of the LC-MS/MS study.

As possible structures and fragmentation patterns were identified by the LC-MS/MS study, this method may help in the development of quality dosage forms, maintaining proper storage conditions, and also in impurity profiling studies.