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A second-generation chlorin-based photosensitizer, 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) has shown tremendous therapeutic potential in clinical trials in the treatment of esophageal cancer. Herein, we have developed and validated a bioanalytical method for estimation of HPPH in rat plasma using High Performance Liquid Chromatography (HPLC) with a photo diode array (PDA) detector. The method was applied for carrying out pharmacokinetic study of HPPH. Further pharmacokinetic modeling was carried out to understand the compartment kinetics of HPPH. The developed method was fully validated as per the United States Food and Drug Administration (US-FDA) guidelines for bioanalytical method validation. The linearity of the method was in the range of 250–8000 ng/mL, and the plasma recovery was found to be 70%. Pharmacokinetic parameters were evaluated and compared via non-compartment analysis and compartment modeling after the intravenous (i.v.) bolus administration in rats using Phoenix WinNonlin 8.0 (Certara™, U.S.A.). From the obtained results, we hypothesize that the HPPH complies with two compartmental pharmacokinetic model. Furthermore, it was observed that HPPH has the rapid distribution from the central compartment to peripheral compartment along with slow elimination from peripheral compartment.

A simple, sensitive and robust HPLC–PDA assay was developed and validated for rapid determination of donepezil hydrochloride (DNP), a potent acetylcholinesterase inhibitor in rat plasma and tissues. All biological samples were prepared by the solid-phase extraction method using loratadine as an internal standard. Separation of the analytes was achieved on a Waters Nova-Pak C18 column (3.9 × 150 mm, 4 μm) using an isocratic mobile phase of acetonitrile and ammonium formate (pH 6.4; 0.01 M) (62 : 38% v/v) at a flow rate of 1 mL min−1. All validation parameter results were within the acceptable range described in the guidelines for bioanalytical method validation. The method showed linearity in the concentration range of 50–5000 ng mL−1 with LOD of 20 ng mL−1 and LLOQ of 50 ng mL−1. Moreover, the advantage of this method over previously published methods is the short analysis run time of 6 min in HPLC itself, alongside its application not only for plasma samples but also in tissues, with low LLOQ. The method was successfully applied for studying the compartmental pharmacokinetics, tissue distribution and pharmacodynamics. A two-compartmental micro model was statistically fitted for the assessment of pharmacokinetic parameters. The tissue distribution studies suggest that the kidneys, lungs and liver are the primarily responsible organs for metabolism and elimination of DNP. Pharmacodynamic studies were performed by measuring acetylcholinesterase inhibitory activity of DNP, which indicated that the pharmacokinetic and pharmacodynamic data are in correlation with each other.

An efficient and highly selective pyrene-thiophene conjugate has been reported as a dual sensor for Hg

Ketorolac, a commonly used anti-inflammatory and analgesic agent, was studied in male wistar rats. The plasma samples were analysed using chiral AGP column with UV detection. The experimental data was analysed for probable fit in the compartmental and non-compartmental models using WinNolin software. The data of (+)-R-Ketorolac and (-)-S-Ketorolac was found to fit into the compartmental as well as non compartmental model. There was a difference between the plasma concentrations of (+)-R-Ketorolac and (-)-S-Ketorolac; the plasma concentrations of (+)-R-Ketorolac were higher than those of (-)-S-Ketorolac throughout the time course of the study. The area under the curve (AUC) of time vs. concentration profile of (+)-R-Ketorolac was found to be higher than (-)-S-Ketorolac. Volume of distribution and clearance was found to be higher for (-)-S-Ketorolac.

A simple, specific, precise, sensitive and rapid reverse phase-HPLC method was developed for determination of ketorolac enantiomers, a potent nonnarcotic analgesic in pharmaceutical formulations. The method was developed on a chiral AGP column. Mobile phase was 0.1 M sodium phosphate buffer (pH 4.5): Isopropanol (98:2, v/v), at a flow rate of 1 mL/min with run time of 15 min. Ultraviolet detection was made at 322 nm. The linearity range was 0.02â10 μg/mL for each of the enantiomers. The mobile phase composition was systematically studied to find the optimum chromatographic conditions. Validation of the method under the conditions selected showed that it was selective and precise and that the detector response was linear function of ketorolac. Keywords: R-Ketorolac, S-Ketorolac, Chiral AGP, RP-HPLC

The difference in tissue distribution of Ketorolac and its enantiomers were investigated in wistar rats. Separate high performance liquid chromatographic method was developed and validated for determination of Ketorolac and its enantiomers. Oyster BDS (150×4.6 mm id., 5 μm particle size) column was used for determination of concentration of Ketorolac. Ketorolac enantiomers were determined using Chiral-AGP column (100×4.0 mm I.D., particle size 5 μ, Chrom tech Ltd, Sweden). Detection was done at wavelength of 322 nm using an ultraviolet detector in the analytical system. Ketorolac enantiomers exhibit difference in their disposition in Wistar rats. In kidney, there was a significant difference in pharmacokinetic parameters. The C max was nearly 4 times and AUC 0–∞ was found to be more than double for S (−) Ketorolac than that of R (+) Ketorolac. MRT, K e and t 1/2 differ significantly in kidney. In liver, C max was found to be approximately 69% higher for S (−) Ketorolac compared to R (+) Ketorolac. AUC 0–∞ did not differ significantly for the enantiomers in liver. In liver, S (−) Ketorolac eliminated very fast in comparison to R (+) Ketorolac having t 1/2 (one third) in comparison to R (+) Ketorolac. In lungs, there was no difference observed for C max and other parameters but AUC 0–∞ was found to be marginally higher for S (−) ketorolac.

A new ultra-performance liquid chromatographyâelectrospray ionization mass spectrometry (UPLCâMS/ESI) method for simultaneous determination of venlafaxine (VEN) and its metabolite O-desmethylvenlafaxine (ODV) in rat plasma has been developed and validated using Venlafaxine d6 as the internal standard. The compounds and internal standard were extracted from plasma by solid phase extraction. The UPLC separation of the analytes was performed on ACQUITY UPLC® BEH Shield RP18 (1.7 µm, 100 mmÃ2.1 mm) column, using isocratic elution with mobile phase constituted of water (containing 2 mM ammonium acetate): acetonitrile (20:80, v/v) at a flow rate of 0.3 mL/min. All of the analytes were eluted within 1.5 min. The compounds were ionized in the electrospray ionization (ESI) ion source of the mass spectrometer, operating in multiple reaction monitoring (MRM) and positive ion mode. The precursor to product ion transitions monitored for VEN, ODV and Venlafaxine d6 were m/z 278.3â121.08, 264.2â107.1 and 284.4â121.0, respectively. The developed and validated method was used for the pharmacokinetic study of VEN in rats. Keywords: Venlafaxine, O-desmethylvenlafaxine, Metabolite, UPLCâMS/ES

The present study deals with the biochemical responses of some selected tree species with respect to increased air pollution in Durgapur industrial city in India. Areas in vicinity to industries possess very high concentrations of suspended particulate matter (571 microg/m3), SOx (132 microg/m3) and NOx (97 microg/m3) which shows significant correlations (p0.05) with the biochemical constituents of stressed plants. Plants growing in industrial zone exhibit a considerable decline in total chlorophyll (34.97-59.81%), soluble sugars (23.85-33.16%) and protein content (21.59-47.13%) and increase in ascorbic acid (81.87-238.53%) and proline content (123.47-284.91%). Of the studied tree species, Shorea robusta (9.78 +/- 0.095), Alstonia scholaris (8.76 +/- 0.084), Peltophorum pterocarpum (8.99 +/- 0.13) and Albizia lebbeck (7.71 +/- 0.012) were found to be more tolerant with higher Air Pollution Toblerance Index (APTI) and Tectona grandis (6.13 +/- 0.276), Lagerstroemia speciosa (7.075 +/- 0.18) and Delonix regia (6.87 +/- 0.079) were sensitive with lower APTI values. Therefore, plant species with higher APTI value, being more resistant, can be used as pollutant absorbent to reduce the pollution level and are suitable for plantations in industrial areas.

In order to screen out the best variety of wheat (Triticum aestivum) out of eight varieties (viz., HP 1633, BW 11, NW 1014, Sonalika, HUW 468, K 9107, HP 1731 and HUW 234), a field experiment was conducted (from Dec. 2002 to April 2003) in a randomized block design replicated thrice at Crop Research and Seed Multiplication Farm, Burdwan University, West Bengal, India. Various morpho physiological parameters viz., plant population, length of shoot and root, leaf area index (LAI), crop growth rate (CGR), leaf area ratio (LAR), leaf area duration (LAD), net assimilation rate (NAR), yield attributes viz., length of panicles, number of grains per panicle, grain yield, straw yield, pigment content in flag leaf (chlorophyll a, b and total chlorophyll and carotenoid content) were estimated and analyzed statistically Soil bacterial populations were also estimated in the fallow land before sowing of seeds and after harvesting of crop. The HUW 468 variety records higher grain yield, maximum panicle length and maximum chlorophyll b and total chlorophyll content.

A new, simple and sensitive spectrofluorimetric method was developed for the routine estimation of etoposide, an anticancer drug, in bulk and in pharmaceutical formulations. The medium selected for the estimation of etoposide was methanol : phosphate buffer (pH 7.4) in a ratio of 70 : 30 v/v. Excitation and emission wavelengths used were 240 and 324 nm respectively. The method was validated according to ICH and U.S.P guidelines. Linearity range was 200-1000 ng/ml with detection and quantitation limits of 23 ng/ml and 72 ng/ml respectively. Regression equation obtained was Fluorescence Intensity = 6.704 (Concentration in ng/ml) + 115.4. The drug was found to be stable and there was no interference from the excipients present in different formulations of etoposide.

The aim of this study was to formulate and evaluate microsphere based depot type parenteral sustained release formulation of diclofenac sodium (DFS). Drug was formulated in the form of microspheres, using varying proportion of ethylcellulose (EC) as the retardant material to extend the release, by phase separation-coacervation technique. The in vitro release pattern of the designed formulations was studied using modified Franz diffusion cell. In vivo pharmacodynamic study was carried out by determining the index of analgesia (increase in response time to thermal stress as percentage of basal response time). Tail flick method was employed to measure both the degree of analgesia and its duration of action. The prepared microspheres were white, free flowing, and spherical in shape with a mean particle size of 50 μm. In vitro release study of the micro-spheres in aqueous media was found to extend the release of DFS beyond 24 hours with DFS and EC ratio 1:3. The plot of log percentage remaining to be released vs. time gave a linear relationship indicating first-order release kinetics. The in vitro release rate constant (Kr) for different microspheres varied between 0.1448 hr-1 and 0.0256 hr-1. A good correlation was obtained between K, and proportion of EC in the microspheres. In vivo pharmacodynamic studies indicated that the duration of analgesic action is prolonged beyond 24 hrs in case of microsphere products of 1:3 ratio of DFS to EC, whereas administration of marketed parenteral preparation showed activity only up to 11hrs. Also, a good correlation was obtained between analgesic activity in vivo and cumulative percentage of drug release from the formulations.

Quantitative structure-activity relationship (QSAR) studies are reported on the benzodiazepine receptor binding of a series of substituted 9-benzyl-6-dimethylamino-9H-purines and N-(indol-3-ylglyoxylyl)amino acid derivatives. The nitrogen of the five membered heterocyclic ring and the polar substituent in the aromatic ring, present in both series of compounds, form important centres in the binding interaction. We conclude that the receptor must possess a strong nucleophilic centre and a polar site, and that a hydrophobic pocket exists to accommodate hydrophobic moieties.

The inhibitory effects of a series of nonspecific local anesthetics on batrachotoxin-elicited sodium flux, batrachotoxin-elicited phosphoinositide breakdown, and on the binding of [3H]batrachotoxin-A 20 alpha-benzoate to sodium channels in guinea pig cerebral cortical synaptoneurosomes are shown to be well-correlated with the molecular size and the hydrophobic character of the molecules. These correlations lead us to suggest that the drug-receptor interaction involves a dispersion interaction, and that the overall effects of local anesthetics is dependent upon their ability to reach the receptor site.

The in vitro antidopamine activity of substituted N-[(1-alkyl-2-pyrrolidinyl)methyl]-6-methoxysalicylamides was found to be well correlated with the hydrophobic and electronic nature of substituents at the 3-position, and with the steric nature of groups replacing the hydrogen atom of the salicyl hydroxy group. In contrast, only the hydrophobic and steric characteristics were found to be important in the in vivo activity of these neuroleptics. This difference suggests that different mechanisms are probably involved in their in vitro and in vivo actions, and that the relevant receptors are slightly different in structure. The in vitro results suggest that electron donation by the 3-substituent strengthens the formation of a hydrogen bond between the carbonyl group of the amide moiety and a hydrogen of the receptor.

The local anesthetic activity of a series of arylquinuclidinylcarbinols is shown to be significantly correlated with their lipophilic character, suggesting that lipophilicity is an important factor for the local anesthetic action of drugs.

(1972). Microwave Transistor Power Amplifier. IETE Journal of Research: Vol. 18, No. 12, pp. 582-587.

By a quantitative structure-activity relationship (QSAR) study, the ability of a series of 1-arylpyrazolo[4,5-c]quinolin-4-ones to displace specific [3H]-flunitrazepam from bovine brain membranes is shown to be significantly correlated with steric and hydrophobic constants of aryl subtituents, suggesting that substituents of 2- and 6-positions produce dominant steric effects and that those of 3- and 5-positions are involved in strong hydrophobic interaction with the receptor.