Cleaning Method Validation for Estimation of Dipyridamole Residue on the Surface of Drug Product Manufacturing Equipment Using Swab Sampling and by High Performance Liquid Chromatographic Technique.

OBJECTIVES: Cleaning validation is the procedure used to ensure that the cleaning process has eliminated the residues of drug substance from on the equipment surface after manufacture. A simple, sensitive, robust, and accurate high performance liquid chromatographic method was developed for the quantitative estimation of dipyridamole in swab samples obtained from the equipment surface after the manufacture of dipyridamole modified release capsules. MATERIALS AND METHODS: The method was developed by using a Hypersil BDS C18 (150×4.6 mm, 5 µm) column with mobile phase containing a mixture of buffer (potassium dihydrogen phosphate buffer, pH 7.0±0.05) and methanol in the ratio of 30:70 v/v. Flow rate was 1.5 mL/min, column temperature was 45°C, and injection volume was 5 µL. RESULTS: The method was validated and a specificity study was conducted to prove that there was no interference from blank and swab blank at the retention time of dipyridamole. The limit of detection and limit of quantification (LOQ) were established by using a series of linearity solutions and were found to be 0.041 µg/mL and 0.124 µg/mL, respectively. The method precision at the LOQ level was 8.6% relative standard deviation (RSD), method precision was 0.2% RSD, and ruggedness was 0.3% RSD. The method was accurate from the concentration of 0.13 µg/mL to 21.80 µg/mL and the recovery results met the acceptance criteria. The linearity of the method was found from 0.12 µg/mL to 20.14 µg/mL and the r2 value was 0.997. The robustness for the flow rate, wavelength, column temperature, buffer pH, and mobile phase ratio variations was tested, and all the system suitability parameters were met. CONCLUSION: The method validation was performed as per the regulatory requirements and guidelines. The validation parameters met the acceptance criteria and the proposed method can be applied for the intended routine swab analysis.

A Facile One-Pot Synthesis of 3-Methylbenzisoxazoles via a Key Intermediate of ortho-Ethoxyvinyl Nitroaryls by Domino Rearrangement and Their Anti- Inflammatory Activity.

BACKGROUND: Recently, there has been a lot of scientific interest in exploring the syntheses of oxygen and nitrogen-containing heterocyclic compounds due to their pharmacological activities. In addition, benzisoxazoles play a very important role in organic synthesis as key intermediates. OBJECTIVE: In this paper, we focused on developing a novel synthetic route for biologically active arylisoxazoles under normal conditions, and simplified it to get high purities and yields, and also reported their anti-inflammatory activities. METHODS: An efficient and simple method has been explored for the synthesis of novel 3-methyl arylisoxazoles from o-nitroaryl halides via o-ethoxyvinylnitroaryls, using dihydrated stannous chloride (SnCl2.2H2O) in MeOH / EtOAc (1:1) via Domino rearrangement in one pot synthesis. RESULTS: We synthesized novel 3-methylarylisoxazoles from o-nitroarylhalides via o-ethoxyvinylnitroaryls, using dihydrated stannous chloride (SnCl2.2H2O) in MeOH / EtOAc (1:1) via domino rearrangement. In this reduction, nitro group and ethoxy vinyl group change to the functional acyl ketones, followed by hetero cyclization. Here, the reaction proceeds without the isolation of intermediates like 2-acylnitroarenes and 2- acylanilines. All the synthesized compounds were completely characterized by the NMR and mass spectra. The compounds were also explored for their anti-inflammatory activity by carrageenan-induced inflammation in the albino rats (150-200 g) of either sex used in this entire study with the use of Diclofenac sodium as the standard drug. The initial evaluations identified leading targets with good to moderate anti-inflammatory activity. CONCLUSION: A simple, one-pot and convenient method has been explored for the synthesis of novel 3- methylarylisoxazoles with high purity and reaction yields. All the compounds 3a, 3c, 3d, 3f, 3g and 3h exhibited 51-64% anti-inflammatory activities.

Analytical Method Development and Validation for the Quantification of Acetone and Isopropyl Alcohol in the Tartaric Acid Base Pellets of Dipyridamole Modified Release Capsules by Using Headspace Gas Chromatographic Technique.

A simple, sensitive, accurate, robust headspace gas chromatographic method was developed for the quantitative determination of acetone and isopropyl alcohol in tartaric acid-based pellets of dipyridamole modified release capsules. The residual solvents acetone and isopropyl alcohol were used in the manufacturing process of the tartaric acid-based pellets of dipyridamole modified release capsules by considering the solubility of the dipyridamole and excipients in the different manufacturing stages. The method was developed and optimized by using fused silica DB-624 (30 m × 0.32 mm × 1.8 µm) column with the flame ionization detector. The method validation was carried out with regard to the guidelines for validation of analytical procedures Q2 demanded by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). All the validation characteristics were meeting the acceptance criteria. Hence, the developed and validated method can be applied for the intended routine analysis.

Design, Synthesis and Biological Evaluation of Novel Urea and Thiourea Bearing thieno[3,2-d]-pyrimidines as PI3 Kinase Inhibitors.

BACKGROUND: Phosphatidylinositol-3-kinase α (PI3Kα) is a ubiquitous intracellular enzyme, mainly involved in intracellular signaling pathways, promotes cellular growth, proliferation, and differentiation. Therefore, inhibition of PI3K can be a hotspot in molecular targeted therapy for the treatment of cancer. METHODS: The present research work involves molecular docking studies performed to screen derivatives of urea and thiourea bearing thieno [3,2-d]-pyrimidines against the active site of PI3K enzyme using MOE.2008.10. The designed structures (6a-f) and (7a-j) were synthesized by the facile synthetic methods and evaluated for their anticancer activity against HT-29 and MCF-7 cell lines and inhibitory activity against PI3Kα enzyme. RESULTS: Among the tested compounds, 4-(4-(2-(3-(pyrimidin-2-yl)thioureido)ethyl)piperazin-1-yl)thieno[3,2- d]pyrimidine-6-carboxamide (7f) showed the highest anticancer activity against HT-29 and MCF-7 cell lines with IC50 values of 2.18 µM and 4.25 µM, respectively. Further, the same compound also exhibited potent PI3Kα inhibitory activity with IC50 value of 1.26 µM. CONCLUSION: Docking studies supported the initial pharmacophoric hypothesis and suggested a mode of interaction at the active binding site of PI3Kα, demonstrating that the target compounds were potential inhibitory agents for cancer therapy.

Design, synthesis, in silico and in vitro evaluation of thiophene derivatives: A potent tyrosine phosphatase 1B inhibitor and anticancer activity.

A series of novel methyl 4-(4-amidoaryl)-3-methoxythiophene-2-carboxylate derivatives were designed against the active site of protein tyrosine phosphatise 1B (PTP1B) enzyme using MOE.2008.10. These molecules are also subjected for in silico toxicity prediction studies and considering their corresponding drug scores, it implied that, the molecules are promising as anticancer agents. The designed compounds were synthesized by using suitable methods and characterized. They were subjected to inhibitory activity against PTP1B and in vitro anticancer activity by MTT assay. Most of the tested compounds showed potent inhibitory activity against PTP1B, among the compounds tested, compound 5b exhibited the highest activity (IC50=5.25µM) and remarkable cytotoxic activity at 0.09µM of IC50 against the MCF-7 cell line. In addition to this, compound 5c also showed potential anticancer activity at 2.22µM of IC50 against MCF-7 and 0.72µM against HepG2 cell lines as well as PTP1B inhibitory activity at IC50 of 6.37µM.