Colorimetric method for the simultaneous determination of chlorphenoxamine hydrochloride and anhydrous caffeine in pure and dosage forms with rose bengal

A rapid, simple and sensitive colorimetric method for the simultaneous determination of chlorphenoxamine HCl and anhydrous caffeine was developed, based on charge-transfer complex formation of the drugs with rose bengal in basic media of pH 9.0. The chlorphenoxamine HCl (I) complex was measured at 588 nm whereas anhydrous caffeine (II) was measured at 551 nm. The optimal experimental parameters for colour production were studied. Beer's law was obeyed in the concentration ranges 2–40 and 2–34 g ml^–1 for I and II, respectively. The Ringbom optimum concentration ranges were 3–36 and 3–30 g ml^–1 for I and II, respectively. The results obtained showed good recoveries of 100.2 ± 1.5 and 99.7 ± 1.3% with relative standard deviations of 0.37 and 0.47% for I and II, respectively. Applications of the method to representative pharmaceutical dosage forms are presented and the validity assessed by applying the standard addition technique.     

Acetylacetone-formaldehyde reagent for the spectrophotometric determination of some sulfa drugs in pure and dosage forms

A new simple and sensitive spectrophotometric procedure for the determination of sulfacetamide sodium (I), sulfadiazine (II), sulfadimidine (III) and sulfathiazole (IV) is based on the reaction of the drug with acetylacetone-formaldehyde reagent to give a yellow product having _max at 400 nm. Optimization of the reaction conditions has been investigated. A linear correlation was obtained between absorbance at _max and the concentration. The Beer's law limits of I, II, III and IV are 4–80, 4–72, 4–60 and 4–80 g/ml, respectively. For more accurate results, Ringbom optimum concentration ranges were evaluated to be 6–76, 8–66, 6–56 and 8–75 g/ml for I, II, III and IV, respectively. The molar absorptivities and Sandell sensitivities for all sulfa drugs under consideration were evaluated. Relative standard deviations of 0.98, 1.07, 0.86 and 0.79% were obtained for I, II, III and IV, respectively. The method has been compared to the official method and found to be simple, accurate (t-test) and reproducible (F-test). The developed procedures were applied for bulk sulfa drugs and some of their dosage forms without interferences from additive and common prescribed drugs.     

Novel Synthesis of Oxothiazolidine Derivatives

(Z)‐Methyl 2‐[3‐(arylideneamino)‐2‐(arylidenehydrazono)‐4‐oxothiazolidin‐5‐ylidene]acetate prepared during the reaction between thiocarbonohydrazides and dimethyl acetylene dicarboxylate. Rational for there conversations involving the nucleophilic addition on C/C triple bond of dimethyl acetylenedicarboxylate are presented.     

Synthesis,PM3‐Semiempirical,and Biological Evaluation of Pyrazolo[4,3‐c]quinolinones

A series of α,β‐unsaturated ketones containing quinolone moieties 2 , 3 , 4 , 5 , 6 were synthesized by condensation of 7‐methoxyquinoline‐2,4(1H,3H)‐dione ( 1 ) with different aryl aldehydes. Pyrazole derivatives 8 , 9 , 10 , 11 were also synthesized via refluxing of α,β‐unsaturated ketones 2 , 3 , 4 , 5 , 6 with hydrazine derivatives. Newly synthesized compounds were characterized by elemental analyses, spectral data, and screened for their antioxidant and antitumor activities. Geometrical optimizations of the molecular structures for different synthesized compounds were studied.     

Synthesis of N‐Substituted(Thiazol‐2‐ylidene)pyrazol‐5‐amine Derivatives via Condensation of Pyrazolylthioureas with ω‐Bromoacetophenones

1‐Substituted 3‐[3‐methyl‐1H‐pyrazol‐5‐yl]thioureas react with ω‐bromoacetophenones forming N‐substituted(thiazol‐2‐ylidene)pyrazol‐5‐amine derivatives. Rational for these conversations are presented.     

Kinetics and mechanism of oxidation of (aqua-2-aminomethyl-pyridine) chromium(III) by N-bromosuccinimide

Summary The kinetics of oxidation of (aqua-2-aminomethyl-pyridine) Cr^III by N-bromosuccinimide (NBS) in aqueous solution to yield chromium(VI) has been studied spectrophotometrically over the 25–40 °C range. The reaction rate is first order with respect to both [NBS] and [Cr^III], and increases with increasing pH between 7.6 and 8.6. The thermodynamic activation parameters were calculated. The experimental rate law is consistent with a mechanism in which the deprotonated [Cr(L)₂(OH)]²⁺ was considered to be the most reactive form compared to its conjugate acid. It is assumed that electron transfer takes place via an inner-sphere mechanism.     

PARP Theranostic Auger Emitters Are Cytotoxic in BRCA Mutant Ovarian Cancer and Viable Tumors from Ovarian Cancer Patients Enable Ex-Vivo Screening of Tumor Response

Theranostics are emerging as a pillar of cancer therapy that enable the use of single molecule constructs for diagnostic and therapeutic application. As poly adenosine diphosphate (ADP)-ribose polymerase 1 (PARP-1) is overexpressed in various cancer types, and is localized to the nucleus, PARP-1 can be safely targeted with Auger emitters to induce DNA damage in tumors. Here, we investigated a radioiodinated PARP inhibitor, [¹²⁵I]KX1, and show drug target specific DNA damage and subsequent killing of BRCA1 and non-BRCA mutant ovarian cancer cells at sub-pharmacological concentrations several orders of magnitude lower than traditional PARP inhibitors. Furthermore, we demonstrated that viable tumor tissue from ovarian cancer patients can be used to screen tumor radiosensitivity ex-vivo, enabling the direct assessment of therapeutic efficacy. Finally, we showed tumors can be imaged by single-photon computed tomography (SPECT) with PARP theranostic, [¹²³I]KX1, in a human ovarian cancer xenograft mouse model. These data support the utility of PARP-1 targeted radiopharmaceutical therapy as a theranostic option for PARP-1 overexpressing ovarian cancers.     

Exact solutions for nonlinear partial fractional differential equations

In this article,we use the fractional complex transformation to convert nonlinear partial fractional differential equations to nonlinear ordinary differential equations.We use the improved(G’/G)-expansion function method to calculate the exact solutions to the time-and space-fractional derivative foam drainage equation and the time-and space-fractional derivative nonlinear KdV equation.This method is efficient and powerful for solving wide classes of nonlinear evolution fractional order equations.     

Modeling and nonlinear control of a flexible-link manipulator

The problem of modeling and controlling the tip position of a one-link flexible manipulator is considered. The proposed model has been used to investigate the effect of the open-loop control torque profile, and the payload. The control strategy is based on the nonlinear State Dependent Riccati Equation (SDRE) design method in the context of application to robotics and manufacturing systems. In this paper, an experimental test-bed was developed to demonstrate the concept of end-point position feedback on a single-link elastic manipulator, and the control strategy for a single-link flexible manipulator. The controller is designed based on the nonlinear SDRE developed by the authors and applied to a flexible manipulator. The experimental results are compared with conventional PD controller strategy. The results reveal that the nonlinear SDRE controller is near optimal and robustly; and its performance is improved comparing to the PD control scheme.