Extractive Spectrophotometric Determination of Omeprazole in Pharmaceutical Preparations

Purpose: To develop a simple, rapid and selective method for the extractive spectrophotometric determination of omeprazole using acidic dyes. Methods: Extractive spectrophotometric determination of omeprazole was developed using acidic dyes - bromophenol blue and orange G - as ion-pairing agents in aqueous medium (pH 7.0 and 6.0, respectively). The ion pair chromogen formed, which was extracted with chloroform, was measured quantitatively at 408 nm and 508 nm, respectively. The developed method was used to analyse commercial omeprazole tablets.Results: Using bromophenol blue and orange G dyes, the ion-paired formed obeyed Beer’s law in the ranges 5 - 30 μg/ml and 50 - 250 μg/ml at 408nm and 503nm, respectively, with molar absorptivities of1.712 × 103 L mol-1 cm-1 and 2.095 × 103 L mol-1 cm-1, respectively, for omeprazole,. The purity of omeprazole obtained was 98.1±0.9 and 99.7±0.3, respectively. Standard deviation (S.D.), % relativestandard deviation (% R.S.D.) and standard error were 0.001 - 0.013, 0.94 - 1.07 % and 4 × 10-4, respectively. The complexes formed were stable for approx. 3 h. Conclusion: Recovery studies gave satisfactory results indicating that none of the major additives/excipients interferred with the assay method. Therefore, a simple, rapid and selective methodwas developed for extractive spectrophotometric determination of omeprazole. This method may be useful for routine laboratory analysis of omeprazole

THE PHARMACEUTICAL AND ANALYTICAL STUDY OF PALASH KSHARA

Background: Kshara is an important dosage form mentioned in Ayurveda which is derived from plant ash. The Kshara have some similar properties like alkaline nature, water solubility, whitish color etc. Kshara are given advantage over all surgical and parasurgical measures as it can be used in thin, weak and patients who fears for surgery. Different herbs like Apamarga, Snuhi, Kadalipalasha are used to prepare Kshara either single or collectively in classical texts. Therapeutic use of Kshara of different herbs differs from each other hence analytical study of each Kshara is necessary. Aims & Objectives: In the present study preparation of Palash (Butea monosperma) kshara and analytical study is done to understand the characteristics of Palashkshara. Material & methods: The preparation of Kshara is a multistep procedure. In the present study preparation of Palasha Kshara is done according general method of preparation of Kshara mentioned in Sharangadhara Sanhita. Prepared Kshara is subjected to various Physico chemical analyses and results are concluded. Results: The Palash Kshara shows physical properties like whitish in color, pungent odor and soft in touch. Chemically it shows combination of Potassium, Phosphate and Sulphate along with other elements in traces. The present study gives the details of methodology and results of the pharmaceutical and analytical study of Palash Kshara

Plasmonic crystals for ultrafast nanophotonics: Optical switching of surface plasmon polaritons

We demonstrate that the dispersion of surface plasmon polaritons in a periodically perforated gold film can be efficiently manipulated by femtosecond laser pulses with the wavelengths far from the intrinsic resonances of gold. Using a time- and frequency- resolved pump-probe technique we observe shifting of the plasmon polariton resonances with response times from 200 to 800 fs depending on the probe photon energy, through which we obtain comprehensive insight into the electron dynamics in gold. We show that Wood anomalies in the optical spectra provide pronounced resonances in differential transmission and reflection with magnitudes up to 3% for moderate pump fluences of 0.5 mJ/cm^2.Comment: 5 pages, 4 figure

Stress degradation of Lisinopril as per ICH Guidelines & Characterisation

Lisinopril an antihypertensive drug was subjected to stress degradation, since the drug is photosensitive undergo hydrolysis and oxidized in presence of oxygen. Hence the objective of the study was to stress degrade Lisinopril and to find out the pathway for stress degradation of Lisinopril. Stress testing methods are screening methods to be used to understand the degradation chemistry of a drug. Lisinopril was subjected to stress degradation under different conditions recommended by International Conference on Harmonization (ICH). The chromatographic separation of Lisinopril and its degradation products was done on C18 column and mobile phase was mixture of Methanol and Water in ratio 80:20, pH 3.5 adjusted with orthophosphoric acid at a flow rate of 1ml/min using UV detector with ?max 220nm. The quantification and characterizations of degraded products were carried out by UV, IR spectroscopy and HPLC. The mechanism of degradation was confirmed by GC-MS fragmentation pattern

Investigation of magnetic anisotropy in Co nanoparticles using ferromagnetic resonance technique

Using ferromagnetic resonance (FMR) technique, we have investigated the temperature dependence and angular dependence of line width and resonance magnetic field of Co nanoparticles capped with novel alkane carboxylic acids of varying chain lengths. The magnetic properties such as blocking temperature and anisotropy sensitively depend on the chain length as evidenced by the temperature dependence of line width. These results indicate that the magnetic properties of these samples are critically governed by the interparticle interactions which are decided by the chain length. The presence of anisotropy even up to very high temperature above the blocking temperature observed in these studies confirms the presence of inter-particle magnetic interactions as well as intra-particle exchange interaction between the core and shell regions as evidenced by our earlier ac susceptibility and transverse susceptibility measurements on similar system

Modulation of a surface plasmon-polariton resonance by sub-terahertz diffracted coherent phonons

Coherent sub-THz phonons incident on a gold grating that is deposited on a dielectric substrate undergo diffraction and thereby induce an alteration of the surface plasmon-polariton resonance. This results in efficient high-frequency modulation (up to 110 GHz) of the structure's reflectivity for visible light in the vicinity of the plasmon-polariton resonance. High modulation efficiency is achieved by designing a periodic nanostructure which provides both plasmon-polariton and phonon resonances. Our theoretical analysis shows that the dynamical alteration of the plasmon-polariton resonance is governed by modulation of the slit widths within the grating at the frequencies of higher-order phonon resonances.Comment: 5 pages, 4 figure

Investigation of magnetic anisotropy in Co nanoparticles using ferromagnetic resonance technique

Using Ferromagnetic Resonance (FMR) technique, we have investigated the temperature dependence and angular dependence of line width and resonance magnetic field of Co nanoparticles capped with novel alkane carboxylic acids of varying chain lengths. The magnetic properties such as blocking temperature and anisotropy sensitively depend on the chain length as evidenced by the temperature dependence of line width. These results indicate that the magnetic properties of these samples are critically governed by the inter-particle interactions which are decided by the chain length. The presence of anisotropy even up to very high temperature above the blocking temperature observed in these studies confirms the presence of inter-particle magnetic interactions as well as intra-particle exchange interaction between the core and shell regions as evidenced by our earlier ac susceptibility and transverse susceptibility measurements on similar system

Interfacing a quantum dot spin with a photonic circuit

A scalable optical quantum information processor is likely to be a waveguide circuit with integrated sources, detectors, and either deterministic quantum-logic or quantum memory elements. With microsecond coherence times, ultrafast coherent control, and lifetime-limited transitions, semiconductor quantum-dot spins are a natural choice for the static qubits. However their integration with flying photonic qubits requires an on-chip spin-photon interface, which presents a fundamental problem: the spin-state is measured and controlled via circularly-polarised photons, but waveguides support only linear polarisation. We demonstrate here a solution based on two orthogonal photonic nanowires, in which the spin-state is mapped to a path-encoded photon, thus providing a blue-print for a scalable spin-photon network. Furthermore, for some devices we observe that the circular polarisation state is directly mapped to orthogonal nanowires. This result, which is physically surprising for a non-chiral structure, is shown to be related to the nano-positioning of the quantum-dot with respect to the photonic circuit