Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2×10^{21} Protons on Target

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3}  eV^{2}/c^{4}.

Combined Analysis of Neutrino and Antineutrino Oscillations at T2K

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135  μ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66  μ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

Measurement of Coherent π^{+} Production in Low Energy Neutrino-Carbon Scattering

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3}  eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3}  eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K.

Angiotensin-converting enzyme (ACE) inhibitory potential of standardized Mucuna pruriens seed extract

CONTEXT

Mucuna pruriens Linn. (Fabaceae) is a tropical legume, traditionally used for controlling blood pressure. Inhibition of angiotensin-converting enzyme (ACE) is one of the successful strategies for controlling hypertension.

OBJECTIVE

The present study evaluated the ACE inhibition potential of the standardized extract of M. pruriens seeds.

MATERIALS AND METHODS

Standardization of the extract and its fractions were carried out by RP-HPLC method [methanol and 1% v/v acetic acid in water (5:95 v/v)] using levodopa as a marker. The ACE inhibition activity of the extract and fractions was evaluated at different concentrations (20, 40, 60, 80, and 100 µg/mL) using the HPLC-DAD and the UV spectrophotometric method. The liberation of hippuric acid (HA) from hippuryl-L-histidyl-L-leucine (HHL) was estimated in the spectrophotometric method and RP-HPLC assay at 228 nm.

RESULTS

Methanol extract and aqueous fraction showed a maximum activity with IC50 values of 38.44 ± 0.90 and 57.07 ± 2.90 µg/mL (RP-HPLC), and 52.68 ± 2.02 and 67.65 ± 2.40 µg/mL (spectrophotometry), respectively.

DISCUSSION

The study revealed that the aqueous extract contains the highest amount of levodopa. Eventually the methanol extract showed highest ACE inhibition activity except levodopa alone. It was further observed that the inhibition was altered with respect to the change in the content of levodopa in the extract. Thus, it can be assumed that levodopa may be responsible for the ACE inhibition activity of M. pruriens seeds.

CONCLUSION

It can be concluded that M. pruriens seed is a potential ACE inhibitor can be explored further as an effective antihypertensive agent.

Measurement of the inclusive electron neutrino charged current cross section on carbon with the T2K near detector

The T2K off-axis near detector ND280 is used to make the first differential cross-section measurements of electron neutrino charged current interactions at energies ∼1  GeV as a function of electron momentum, electron scattering angle, and four-momentum transfer of the interaction. The total flux-averaged ν(e) charged current cross section on carbon is measured to be ⟨σ⟩(ϕ)=1.11±0.10(stat)±0.18(syst)×10⁻³⁸ cm²/nucleon. The differential and total cross-section measurements agree with the predictions of two leading neutrino interaction generators, NEUT and GENIE. The NEUT prediction is 1.23×10⁻³⁸ cm²/nucleon and the GENIE prediction is 1.08×10⁻³⁸ cm²/nucleon. The total ν(e) charged current cross-section result is also in agreement with data from the Gargamelle experiment.

RP-HPLC simultaneous estimation of betulinic acid and ursolic acid in Carissa spinarum

Carissa spinarum is a well-known medicinal plant which has been reported for its anthelmintic, antipyretic, antiviral, antimicrobial and antitumour activities. In this study, a reverse-phase high-performance liquid chromatographic method was developed for the simultaneous estimation of betulinic acid (BA) and ursolic acid (UA) in the methanol extract of C. spinarum root. The method was further validated for linearity, limit of detection (LOD = 3.3σ/S), limit of quantification (LOQ = 10σ/S), precision, accuracy and ruggedness. The linear response was obtained using the equation, y = 511.5x+17603 (r(2) = 0.9920) and y = 2886x+6821 (r(2) = 0.9935) for BA and UA, respectively. The LOD and LOQ were found to be 0.268 ± 0.520 μg mL(-1), 0.878 ± 0.183 μg mL(-1) for BA (0.58% w/w) and 3.140 ± 0.36 μg mL(-1), 8.820 ± 0.85 μg mL(-1) for UA (1.09% w/w), respectively. The %RSD of precision and recovery of BA and UA was < 2.0%. The proposed method was simple, accurate, specific, precise and reproducible.

Anti-cholinesterase activity of the standardized extract of Syzygium aromaticum L

BACKGROUND

Clove (Syzygium aromaticum) is a well-known culinary spice with strong aroma; contains a high amount of oil known as clove oil. The major phyto-constituent of the clove oil is eugenol. Clove and its oil possess various medicinal uses in indigenous medicine as an antiseptic, anti-oxidant, analgesic and neuroprotective properties. Thus, it draws much attention among researchers from pharmaceutical, food and cosmetic industries.

OBJECTIVE

The aim of the present study was to determine the anti-cholinesterase activity of the methanol extract of clove, its oil and eugenol.

MATERIALS AND METHODS

In vitro anti-cholinesterase activity of S. aromaticum was performed by a thin layer chromatography bio autography, 96 well micro titer plate and kinetic methods. Reverse phase high performance liquid chromatography (RP-HPLC) analysis was carried out to identify the biomarker compound eugenol in clove oil.

RESULTS

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition study revealed that eugenol possess better inhibition of the enzymes than extract and oil. Clove extract, its oil and eugenol showed better inhibition of AChE than BChE. Polyphenolic compound eugenol was detected through RP-HPLC analysis. The content of eugenol in essential oil was found to be 0.5 μg/ml. Kinetic analysis of the cholinesterase inhibition study of the extract; clove oil and eugenol have shown that they possess mixed type of inhibition for AChE and non-competitive type of inhibition for BChE.

CONCLUSION

These results might be useful in explaining the effect of clove as anti-cholinesterase agent for the management of cognitive ailments like Alzheimer's disease.

Cytochrome P450 inhibitory potential and RP-HPLC standardization of trikatu--a Rasayana from Indian Ayurveda

ETHNOPHARMACOLOGICAL RELEVANCE

Trikatu is a very well known 'Rasayana' in Ayurveda and widely used as a polyherbal ayurvedic formulation in India. It consists of three well known plants, viz., Piper longum (PL), Piper nigrum (PN) and Zingiber officinale (ZO) in equal ratio. Trikatu has been prescribed for cough, cold, fever, asthma, respiratory problems and improvement of digestive disorders. The aim of the present study was to investigate the effect of individual ingredients of trikatu namely PL, PN, and ZO and formulations [Marketed formulation (MF) and laboratory formulation (LF)] on drug metabolizing enzymes (CYP3A4 and CYP2D6), to assess its herb-drug interaction potential through cytochrome P450 inhibition assays. Further this work was aimed to develop an RP-HPLC method for the identification and quantification of piperine and 6-gingerol in the crude drug trikatu.

MATERIALS AND METHODS

Enzyme inhibition effect of LF, MF, PL, PN and ZO was explored through CYP450-CO complex assay using rat liver microsomes (RLM) and a fluorescence screening method using individual isoenzymes (CYP3A4 and CYP2D6). The RP-HPLC method was developed for the identification and quantification of piperine and 6-gingerol in LF, MF and individual plant materials at the concentration of 1mg/mL.

RESULTS

RP-HPLC analysis confirmed the presence of piperine and 6-gingerol in LF and MF [Piperine: 7.89±2.12% (w/w) (MF), 6.70±2.13% (w/w) (LF)]; [6-gingerol: 5.3±1.21% (w/w) (MF), 4.95±2.34% (w/w) (LF)]. Inhibitory potential of MF and LF in CYP450-CO complex assay was found to be 37.54±3.12% (MF) and 35.12±2.31% (LF) and against CYP2D6 and CYP3A4 was estimated to be IC50 251.30±3.98 and 245.23±1.92μg/mL and IC50 225.50±1.02 and 223.254±0.92μg/mL respectively.

CONCLUSIONS

Different concentrations of the trikatu formulation and its individual components showed significantly (p<0.001) less inhibitory activity on individual isoenzymes as compared to the positive control. The crude drug exhibited inhibitory potential against the CYP450 enzymes in a concentration dependent manner. Outcome of the present study demonstrated that trikatu has less interaction potential with drug metabolizing enzymes.

Precise measurement of the neutrino mixing parameter θ23 from muon neutrino disappearance in an off-axis beam

New data from the T2K neutrino oscillation experiment produce the most precise measurement of the neutrino mixing parameter θ23. Using an off-axis neutrino beam with a peak energy of 0.6 GeV and a data set corresponding to 6.57×10(20) protons on target, T2K has fit the energy-dependent νμ oscillation probability to determine oscillation parameters. The 68% confidence limit on sin(2)(θ23) is 0.514(-0.056)(+0.055) (0.511±0.055), assuming normal (inverted) mass hierarchy. The best-fit mass-squared splitting for normal hierarchy is Δm32(2)=(2.51±0.10)×10(-3)  eV(2)/c(4) (inverted hierarchy: Δm13(2)=(2.48±0.10)×10(-3)  eV(2)/c(4)). Adding a model of multinucleon interactions that affect neutrino energy reconstruction is found to produce only small biases in neutrino oscillation parameter extraction at current levels of statistical uncertainty.

Observation of electron neutrino appearance in a muon neutrino beam

The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3σ when compared to 4.92±0.55 expected background events. In the Pontecorvo-Maki-Nakagawa-Sakata mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles θ12, θ23, θ13, a mass difference Δm(32)(2) and a CP violating phase δ(CP). In this neutrino oscillation scenario, assuming |Δm(32)(2)|=2.4×10(-3)  eV(2), sin(2)θ(23)=0.5, and Δm322>0 (Δm(32)(2)<0), a best-fit value of sin(2)2θ(13)=0.140(-0.032)(+0.038) (0.170(-0.037)(+0.045)) is obtained at δ(CP)=0. When combining the result with the current best knowledge of oscillation parameters including the world average value of θ(13) from reactor experiments, some values of δ(CP) are disfavored at the 90% C.L.

Measurement of neutrino oscillation parameters from muon neutrino disappearance with an off-axis beam

The T2K Collaboration reports a precision measurement of muon neutrino disappearance with an off-axis neutrino beam with a peak energy of 0.6 GeV. Near detector measurements are used to constrain the neutrino flux and cross section parameters. The Super-Kamiokande far detector, which is 295 km downstream of the neutrino production target, collected data corresponding to 3.01×10(20) protons on target. In the absence of neutrino oscillations, 205±17 (syst) events are expected to be detected while only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum, assuming three neutrino flavors and normal mass hierarchy yields a best-fit mixing angle sin2(θ23)=0.514±0.082 and mass splitting |Δm(32)(2)|=2.44(-0.15)(+0.17)×10(-3) eV2/c4. Our result corresponds to the maximal oscillation disappearance probability.

Angiotensin Converting Enzyme Inhibition Activity of Fennel and Coriander Oils from India

Foeniculum vulgare Mill and Coriandrum sativum L. are very popular spices in Indian kitchens. The present study was an attempt to evaluate the angiotensin converting enzyme (ACE) inhibition and antioxidant activity of the standardized oils of F. vulgare and C. sativum by an UV method using hippuryl-L-histidyl-L-leucine (HHL) as substrate. Standardization of the oils and identification of the chemical-markers (linalool and anethole) present in them was performed through HPLC and GC-MS. Coriander oil showed the higher ACE inhibition with an IC50 value of 34.8 ± 2.3 μg/mL, than fennel oil with an IC50 value of 40.7 ± 3.5 μg/mL. Both oils showed strong DPPH radical scavenging activity. This finding suggests that coriander and fennel oils can be potential leads for the management of hypertension as an ACE inhibitor.

Indication of electron neutrino appearance from an accelerator-produced off-axis muon neutrino beam

The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3)  eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy.

Exploring the potential of Nelumbo nucifera rhizome on membrane stabilization, mast cell protection, nitric oxide synthesis, and expression of costimulatory molecules

Immunomodulatory activity of Nelumbo nucifera rhizome was evaluated for its standardized extract (NNRE) with respect to betulinic acid. Various key parameters including erythrocyte membrane stabilization, inhibition of histamine release, reduction in nitric oxide production and depletion of expression of costimulatory molecules of macrophages were estimated. The result displayed that NNRE stabilized erythrocyte membrane significantly at 10 (42.05%) and 100 microg/mL (44.31%). Although considering the protection of mast cells from degranulation, NNRE showed 38.66% (100 microg/mL) and 69.66% (10 microg/mL) degranulation against compound 48/80 (C 48/80). NNRE at 1 and 5 microg/mL inhibited lipopolysaccharide (LPS)-induced activation of macrophages by decreasing the expression of costimulatory molecules. Expression of CD40, CD80, and CD86 by NNRE was seen significantly at 5 microg/mL compared to LPS-treated group. The extracts also inhibited the nitrite concentration at 1 and 5 microg/mL compared to LPS-treated group.

Anticholinesterase activity of standardized extract of Illicium verum Hook. f. fruits

Illicium verum is a well known spice in traditional Indian system for its therapeutic potential. The present study was aimed to evaluate the acetylcholinesterase (AChE) and butyrylcholinesterase inhibitory (BChE) activity of standardized extracts of I. verum and its oil. Present study confirmed that anethole contributed to the anticholinesterase activity of I. verum, with more specificity towards AChE. IC(50) for AChE and BChE inhibitory activity of anethole was 39.89±0.32 μg/mL and 75.35±1.47 μg/mL, whereas for the oil, 36.00±0.44 μg/mL and 70.65±0.96 μg/mL respectively. Therefore I. verum can be a good lead as anti-cholinesterase agent from natural resources.

Acetylcholinesterase enzyme inhibitory potential of standardized extract of Trigonella foenum graecum L and its constituents

Ethno pharmacological approach has provided several leads to identify potential new drugs from plant sources, including those for memory disorders. Acetylcholinesterase inhibitors (AChEI) give a symptomatic relief to some of the clinical manifestations of the disease. The main objective of this study is to standardize the extract of Trigonella foenum graecum L with trigonelline by HPTLC method and determine the in vitro AChE inhibitory activity of Trigonella foenum graecum L and its constituents using galanthamine as a reference. Different concentrations of hydro alcoholic extract of Trigonella foenum graecum and trigonelline were subjected to HPTLC analysis using the mobile phase n propanol, methanol and water (4:1:2, v/v). The R(f) of trigonelline was found to be 0.43, and the correlation coefficient of 0.99 was indicative of good linear dependence of peak area on concentration. The concentration of trigonelline was found to be 13mgg(-1)w/w in the hydro alcoholic extract of Trigonella foenum graecum. The AChE inhibitory activity of crude fenugreek seed extracts, fractions and trigonelline was evaluated using Ellman's method in 96-well micro plate's assay and TLC bioassay detection. The ethyl acetate fraction of the alcohol extract (IC50 53.00 +/- 17.33microg/ml), and total alkaloid fraction (IC50 9.23+/-6.08microg/ml) showed potential AChE inhibition. Trigonelline showed IC50 233+/-0.12microM. Galanthamine was used as standard and it showed inhibition of acetyl cholinesterase with an IC50 value of 1.27+/-0.21microM.

Inclusive K(S);(0)K(S);(0) resonance production in ep collisions at HERA

Inclusive K_{S};{0}K_{S};{0} production in ep collisions at the DESY ep collider HERA was studied with the ZEUS detector using an integrated luminosity of 0.5 fb;{-1}. Enhancements in the mass spectrum were observed and are attributed to the production of f_{2}(1270)/a_{2};{0}(1320), f_{2};{'}(1525) and f_{0}(1710). Masses and widths were obtained using a fit which takes into account theoretical predictions based on SU(3) symmetry arguments, and are consistent with the Particle Data Group values. The f_{0}(1710) state, which has a mass consistent with a glueball candidate, was observed with a statistical significance of 5 standard deviations. However, if this state is the same as that seen in gammagamma-->K_{S};{0}K_{S};{0}, it is unlikely to be a pure glueball state.

Pharmacological validation of Kantha chendooram for antiulcer activity in modified pylorus ligated (shay) rat model

The use of metals and minerals is predominant in siddha system of medicine. As per siddha concept, peptic ulcer is known as Valigunmam, the basic abnormality appears to be the derangement of metabolism in the stomach and duodenum resulting in malfunctioning of the secretory process of gastric mucosa. Chendooram is a group of siddha drugs which is used for anemia, obesity, rheumatic diseases; abdominal tumours etc.During the present study standardized Kantha chendooram was selected and evaluated for its anti-ulcer activity, which could not be attempted by researchers earlier.

PEGylated Peptide Dendrimeric Carriers for the Delivery of Antimalarial Drug Chloroquine Phosphate

PURPOSE

The present study was aimed at developing and exploring the use of uncoated and chondroitin sulfate A (CSA) coated PEGylated poly-L-lysine-based dendrimers for controlled and sustained delivery of a blood schizonticide, chloroquine phosphate (CQ).

METHODS

The poly-L-lysine-based peptide dendrimers with PEG amine core prepared and coated with CSA were used to encapsulate the drug molecules by dialysis method. Effect of CSA coating on the surface characteristics, drug entrapment, drug release, stability, hemolytic toxicity, macrophageal interactions, and cytoadherence were determined and compared with those of uncoated systems.

RESULTS

The CSA coating of the carriers was found to increase size and drug loading capacity, and reduce drug release rate and hemolytic toxicity. Transmission electron microscopic study revealed the surface properties of the systems. Stability studies had shown increased stability of the formulations on CSA coating. There was a significant reduction in hemolytic toxicity and cytotoxicity of CQ by the present dendrimeric carriers, which became more prominent on further CSA conjugation of the equivalent drug-loaded dendrimeric carriers. There were also significant reduction in levels of ring and trophozoite stages of Plasmodium falciparum in liquid culture when treated with CSA coated dendrimers because of the expression of similar carbohydrate receptors as that by placental and cerebral barriers for infected red blood cells. The systems were also found suitable for prolonging and controlling the blood level of drug as indicated by blood level and organ distribution studies in albino rats on intravenous administration, precluding any significant hematological or toxicological manifestations.

CONCLUSION

Thus it can be said that CSA coating can improve drug-loading capacity, control and sustain the release of CQ from such carriers, and can suitably act as safer and effective carriers for intravenous CQ administration.

Glycodendrimeric nanoparticulate carriers of primaquine phosphate for liver targeting

In the present study it was intended to deliver primaquine phosphate (PP), a liver schizonticide directly to liver cells using polypropyleneimine (PPI) dendrimers-coated peripherally with galactose. PPI dendrimers were synthesized by consecutive Michael double addition reaction (using ethyelenediamine as core), followed by hydrogenation reaction. Galactose conjugation was carried out by ring opening reactions, followed by Schiff's reaction and reduction to secondary amine in sodium acetate buffer (pH 4.0). IR, NMR, MASS spectroscopy were used for the confirmation of synthesis of uncoated and coated dendrimers. The formulations were made by equilibrium dialysis of dendrimers with the solution of PP. Then the formulations were characterized by TEM for size and shape. Release rate, hemolytic toxicity; bio-distribution and blood level studies were also performed on lyophilized formulations. The results obtained indicated that galactose coating of PPI systems increases the drug entrapment efficiency by 5-15 times depending upon generations. Galactose coating prolonged release up to 5-6 days as compared to 1-2 days for uncoated PPI systems. The hemolytic toxicity, blood level and hematological studies proved these systems to be safer and suitable for sustained drug delivery. Blood level studies proved the suitability of the systems for the prolonged circulations and delivery of PP to liver. The galactose coating of PPI dendrimers can therefore make the PPI systems more effective and suitable for targeted delivery of Primaquine phosphate to liver.

Chitosan hydrochloride based microspheres of albendazole for colonic drug delivery

Microspheres of chitosan hydrochloride (CH) were prepared in order to deliver albendazole specifically into the colon. Microspheres were prepared by an emulsion method using different ratios of drug and CH (1:1 to 1:5), agitation speeds (500 to 1500 rpm) and concentrations of glutaraldehyde in toluene as the cross-linking agent (0.25 to 1.0% w/v). The effect of polymer concentration, stirring rate and concentration of cross-linking agent on the particle size and drug loading was studied. With an increase in CH concentration, the average particle size was increased. Increased agitation speed reduced the size of the microspheres but higher agitation speed resulted in irregularly shaped microspheres. Increasing the concentration of cross-linking agent produced more regularly shaped microspheres of smaller size. The drug loading was highest at a drug: CH ratio of 1:3, stirring speed 1000 rpm and 0.75% w/v concentration of cross-linking agent. The effect of CH concentration on in vitro drug release from the microspheres was evaluated in simulated g.i.t fluids. A comparative in vitro drug release study of the optimized formulation was carried out in simulated colonic fluid, with and without 2% rat caecal content. The drug release in 24 h was 48.9% in colonic fluid without rat caecal content, and 76.5% in colonic fluid with rat caecal contents.

A PEGylated dendritic nanoparticulate carrier of fluorouracil

The present study was aimed at developing and exploring the use of uncoated and PEGylated newer PAMAM dendrimers for delivery of anti-cancer drug 5-fluorouracil. For this study, successive Michael addition and exhaustive amidation reactions were used to synthesize 4.0 G PAMAM dendrimers, using ethylenediamine as core and methylmethacrylate as propagating agent. The dendrimer was PEGylated using N-hydroxysuccinimide-activated carboxymethyl MPEG-5000. IR and NMR data proved the synthesis. Various physicochemical parameters, SEM, TEM, lambda(max) values, hemolytic toxicity, drug entrapment, drug release and blood-level studies of both PEGylated and non-PEGylated systems were determined and compared. The PEGylation of the systems was found to have increased their drug-loading capacity, reduced their drug release rate and hemolytic toxicity. TEM study revealed surface properties of the systems. Stability studies had shown its stability at room temperature in dark. The systems were found suitable for prolonged delivery of an anti-cancer drug by in vitro and blood-level studies in albino rats, without producing any significant hematological disturbances. PEGylation has been found to be suitable for modification of PAMAM dendrimers for reduction of drug leakage and hemolytic toxicity. This, in turn, could improve drug-loading capacity and stabilize such systems in body. The study suggests use of such PEGylated dendrimeric systems as nanoparticulate depot type of system for drug administration.

Pegnology: a review of PEG-ylated systems

Polyethylene glycol conjugation or linking with the system is called PEGylation. Many novel drug systems are used for the delivery of drugs and bioactive substances to particular sites in a controlled or sustained manner, but various side effects or shortcomings restrict their use for the intended purpose. The shortcomings such as RES uptake, drug leakage, immunogenicity, stability, hemolytic toxicity etc. can generally be overcome by PEGylation of novel drug delivery systems such as liposomes, proteins, enzymes, drugs, nanoparticles etc. In this article the whole aspect of PEGylation starting from activation and derivatisation of poly (ethylene glycol) to the linking and designing of systems and their purification and characterization is discussed. The various properties of Pegylated systems are also discussed.