Ternary Metal (W-Ni-Sr) Oxide@Polypyrrole Nanotubes: A New Frontier in the Electrochemical Detection of Promethazine Hydrochloride (PMHC) Shilpa Purushothama, Sirisha Subbareddy, Santhosh Arehalli Shivamurthy, Sandeep Shadakshari, Shruthi Chinnakurli Dwarakanath, et al. Langmuir, 2025 Promethazine hydrochloride (PMHC) is a vital drug that is used as an anticholinergic, antipsychotic, antihistaminic, analgesic, sedative, and neuroleptic. However, the overdosage of PMHC also causes reproductive variations, cardiac changes, hypotension, and endocrinal variations. Hence, the detection of PMHC is crucial. Therefore, in this work an electrochemical method for the detection of PMHC is reported. The fabrication for the modified electrode is built with tungsten (W), nickel (N), and strontium (S) ternary oxide (tWNSO). To the best of our knowledge, this tWNSO ternary oxide preparation is reported for the first time in the literature. The prepared ternary oxide is deposited on the polypyrrole nanotubes, and this nanocomposite that is formed is confirmed by various physical characterizations like XRD, SEM, TEM, UV-vis spectroscopy, FTIR spectroscopy, and also DFT studies for PMHC. Thus, the nanocomposite obtained is used as a working electrode for the detection of PMHC. The fabricated tWNSO/PPyNTs/GCE has an effective surface area of 0.0436 cm2. Also, no fouling was observed. The limit of detection of the analyte PMHC is 3.66 nM, the limit of quantification is 11.10 nM, and the sensitivity of the fabricated electrode in identifying the analyte is found to be 20.10 μA μM-1 cm-2. Thus, the modified working electrode effectively detects the analyte PMHC while demonstrating excellent stability and reproducibility.
Stability Indicating Method Development and Validation for Quantification of Impurities in Melitracen Hydrochloride, An Antidepressant Drug Using Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) Bhaskar Mangalapu, B. Srinivas, Sirigiri Ramathulasi, Ramesha Andagar Ramakrishna, Venkata Narayana Palakollu Research Journal of Pharmacy and Technology, 2025 Anxiolytic and antidepressant uses for melitracen hydrochloride are the main ones. It helps treat anxiety and depression symptoms by adjusting the activity of certain neurotransmitters, mainly norepinephrine and serotonin. To increase the treatment's therapeutic efficacy, it is frequently used in combination with other drugs. A simple, specific, and accurate stability indication of the RP HPLC method was developed to quantify melitracen hydrochloride (MH) and its associated process impurities, aiming to provide a precise and reliable analytical tool for this bulk drug. This method adheres to the International Conference on Harmonization Guidelines (ICH). The X-Terra RP 18 column from Waters Corporation (15cm x 0.46cm i.d., 5µm particle size) was used to establish an isocratic RP-HPLC on a Shimadzu HPLC system. The mobile phase contained a mixture of buffer, Acetonitrile 35:65; the buffer preparation was prepared weighed 5.23g of potassium phosphate dibasic in 1000 ml of water, stirred well, and the pH was adjusted to 7.0 using orthophosphoric Acid (phosphoric Acid, H₃PO₄). A mobile phase was made (35:65), with Acetonitrile at 35 volumes and buffer at 65 volumes. The peak elution was observed at 220nm, with a 1.2ml/min flow rate; Impurity A 3.89 minutes, impurity B 32.85 minutes, and MH 20.69 minutes were determined to have retention times, respectively. The calibration curve used to assess MH and its related impurities (Impurity A: 10-(3-(dimethylamino) propyl)-9,10-dihydro-9,9-dimethylanthracen-10-ol, and Impurity B: 10,10-dimethyl anthrone), demonstrates a straight line across the concentration range of 5µg/ml to 200µg/ml, with an r2 value of 0.999. The limit of quantification is 29.68µg/ml for MH, 7.95µg/ml for Impurity A, and 17.08µg/ml for Impurity B. Statistical analysis has been conducted on the outcomes obtained from our proposed methodologies. The API drugs were subjected to Acid, base, thermal, UV, sunlight, and peroxide degradation. The degradation studies indicated MH showed degradation only in peroxide conditions. With notable variations in their retention time values, the degradation products from the pure medication were clearly separated. Melitracen hydrochloride can be quantitatively analyzed simultaneously in bulk medications with success when using this approach.
The development of a GC-FID method for indirect quantification of chloroacetyl chloride, a potential genotoxic impurity, in chlordiazepoxide hydrochloride drug substance Srinivas Birudukota, Bhaskar Mangalapu, Ramesha Andagar Ramakrishn, Swagata Halder, Venkata Narayana Palakollu Journal of Applied Pharmaceutical Science, 2024 This study presents an innovative gas chromatographic-flame ionization detection (GC-FID) method, developed and validated in accordance with The International Council for Harmonisation (ICH) guidelines, for the quantitative analysis of chloroacetyl chloride, a potentially genotoxic impurity, in chlordiazepoxide hydrochloride active pharmaceutical ingredient. Due to the reactive and genotoxic nature of chloroacetyl chloride, precise quantification is imperative in the active pharmaceutical ingredient. The proposed method involves the conversion of chloroacetyl chloride into methyl 2-chloroacetate (MCA), enabling indirect quantification via a GC-FID approach employing a DB wax column. The validated GC-FID method displays exceptional features, such as remarkable linearity, ranging from 0.38 to 1.8 ppm with a correlation coefficient of 0.9998, as well as low detection and quantification limits of 0.19 and 0.38 ppm, and the method is specific without interference. The precision of the method expressed as the % RSD was 0.53%. The sample recovery ranging from 97.3% to 101.5%, confirms the method’s accuracy. Furthermore, three different batches of chlordiazepoxide hydrochloride underwent evaluation using this method. In conclusion, this method offers a highly sensitive approach for the precise quantification of chloroacetyl chloride in chlordiazepoxide hydrochloride drug substance, thereby ensuring compliance with the stringent safety standards of the pharmaceutical industry.
Electrochemical immunosensing of tumor markers Venkata Narayana Palakollu, Y. Veera Manohara Reddy, Mehdihasan I. Shekh, S.V. Prabhakar Vattikuti, Jaesool Shim, et al. Clinica Chimica Acta, 2024
Tuning the Surface Functionality of Fe3O4 for Sensitive and Selective Detection of Heavy Metal Ions Manjunatha Kumara K. S., D. H. Nagaraju, Zhoveta Yhobu, Nayan Kumar H. N., Srinivasa Budagumpi, et al. Sensors, 2022 The functionalization of materials for ultrasensitive detection of heavy metal ions (HMIs) in the environment is crucial. Herewith, we have functionalized inexpensive and environmentally friendly Fe3O4 nanoparticles with D-valine (Fe3O4–D–Val) by a simple co-precipitation synthetic approach characterized by XRD, FE-SEM, and FTIR spectroscopy. The Fe3O4–D–Val sensor was used for the ultrasensitive detection of Cd+2, Pb+2, and Cu+2 in water samples. This sensor shows a very low detection limit of 11.29, 4.59, and 20.07 nM for Cd+2, Pb+2, and Cu+2, respectively. The detection limits are much lower than the values suggested by the world health Organization. The real water samples were also analyzed using the developed sensor.
