Synthetic Pharmaceutical Samples Research Articles

A Selective Membrane Electrode for Iodide Ion based on New Ionophore and its Application to Pharmaceutical Samples

Background and Objectives: On the basis of newly synthesized i.e. imidazolidine-2tion (IMT), highly selective poly vinyl chloride (PVC) membrane electrode was utilized as a carrier for iodide selective electrode via the incorporation of membrane ingredients within the graphite electrode surface. Method: The impact of different factors consisting of the pH, membrane arrangement and likely intervening anions were examined on the electrode’s response characteristics. The created sensor displayed Nernstian responses to iodide across a concentration of 1× 10-6 to 0.1 M with slopes of 57.8± 0.7 mV per iodide concentration decade and 7 × 10-7M detection limit, across a pH range of 3.0-10.5. Results: The sensor response time was 6 seconds and may be used for a minimum of 2 months with no significant divergence at potential responses. Conclusion: The electrode was implemented with success to determine iodide within synthetic pharmaceutical samples as well as using as an indicator electrode for precipitation titration.

Sensitive electrochemical platform based on nano-cylindrical strontium titanate/N-doped graphene hybrid composite for simultaneous detection of diphenhydramine and bromhexine

Herein, we report a nano-cylindrical strontium titanate/N-doped graphene (SrTiO3/N-GNS) hybrid composite synthesized by a solvothermal method. The composite material has been explored by various physicochemical and electrochemical characterization techniques. It is found that the nano-cylindrical SrTiO3 nanoparticles with highly crystalline mesoporous structure are consistently present in between as well as on the surface of N-GNS sheets resulted in 3-dimensional continuous structure. The electrochemical investigations reveal that SrTiO3/N-GNS hybrid composite displays excellent electrocatalytic behavior towards simultaneous electro-oxidation of two commonly encountered anti-allergic drugs viz. Diphenhydramine (DPH) and Bromhexine (BRO) in phosphate buffer of pH 7.0 employing adsorptive stripping differential pulse voltammetry. The new application of SrTiO3/N-GNS hybrid as an electrochemical sensor shows wide linear working range from 0.038 to 100.0 μM for DPH and 0.030–90.0 μM for BRO with detection limit of 2.1 and 1.9 nM respectively. Also, the developed sensor manifests adequate recoveries in synthetic pharmaceutical samples and human body fluids. These findings suggest that SrTiO3/N-GNS composite is and could serve as a potential candidate for highly sensitive electrochemical sensing applications.

REVERSED-PHASE SEQUENTIAL INJECTION LIQUID CHROMATOGRAPHIC METHOD FOR SILDENAFIL ASSAY

Sequential injection chromatography (SIC) has been recently proposed as an alternative separation technique with potential benefits and some limitations. In the current study, a more pressure resistant selection valve (SV) with additional ports was installed in an SIC assembly. The current SV allowed using a buffer in a Mobile phase (MP) without leakage and analyzing ten solutions with a one-shot run. In addition, a new method for sildenafil assay in tablets, bulk, and synthetic pharmaceutical samples was proposed utilizing the newly developed SIC assembly. Response surface approach was adopted to screen the effect of MP composition on tR, PH, and B and, accordingly, to optimize the method. Sample volume and flow rate were optimized using the univariate approach. The optimum chromatographic conditions were: C18 monolithic column (4.6 × 25 mm), an MP composition of 0.3 M ammonium acetate:acetonitrile (50:50, v/v) at pH 6.8, sample volume 40 µL and flow rate 40 µL/s. UV detection at 240 nm was carried out using miniaturized fiber optic spectrometric devices. A comparative study on some analytical features of the SIC method with those of previous HPLC methods was conducted. The SIC method is more rapid and more reagent-saving and thus safer to the environment. The sample frequency was 40 samples/hr. The total volume of consumed reagents and sample was 2.54 mL.