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Biomedical subjects

S C Chattaraj

Publications and source records attributed to S C Chattaraj.

7 recordsLinked to original sources
PubMed2001

Cangrelor AstraZeneca.

AstraZeneca is developing the P2T (P2YADP) purinoceptor antagonist and platelet aggregation inhibitor, cangrelor, for the potential treatment of unstable angina and as an ultrafast-acting intravenous antithrombotic agent. It is in phase IIb clinical trials [315723]. NDA and MAA applications are planned for after 2003 [275466], [314472]. It superseded the earlier compound, ARL-67085, which also reached phase II trials [328760]. In ex vivo samples of angina patients' blood, cangrelor inhibits platelet/monocyte conjugate development, which indicate the drug has some degree of disease-modifying activity [377418]. AstraZeneca is also developing derivatives of cangrelor. Removal of the triphosphate side chain, modification of the ribose to a carbocycle and the purine to a triazolopyridine resulted in a potent (IC50 = 4 nM) orally-active P2T/P2Y12 receptor antagonist. A lead compound was scheduled to enter trials as an antithrombotic agent in July 2000 [377666]. In March 1999, Lehman Brothers predicted a 30% probability that the drug would reach world markets and would be launched in 2002 [336599].

Adenosine Monophosphate↗
PubMed1999

Biodegradable microparticles of influenza viral vaccine: comparison of the effects of routes of administration on the in vivo immune response in mice.

The objective of this study was to investigate the comparative immune response following administration of biodegradable microparticles loaded with influenza viral vaccine using subcutaneous and oral routes. Influenza viral vaccine was entrapped in poly(d,l-lactide-co-glycolide) (PLG) and poly(isobutylcyanoacrylate) (PIBCA) microparticles. Stability and immunogenicity of entrapped antigen were retained, as evaluated by SDS-PAGE and immunoblot. Microparticles in the size range of <11 microm were evaluated for protein loading and in vitro antigen release. The mice were immunized with microparticle loaded antigen and IgG levels in blood and IgA levels in saliva and gastric secretions were monitored by ELISA method. When the mice were immunized with microparticle suspensions, IgG levels were higher if administered by subcutaneous primed by oral route compared to oral primed by subcutaneous route or subcutaneous or oral route. The IgA level in saliva and gastric secretions were also found to be higher when subcutaneous immunization was given followed by oral booster than oral priming followed by subcutaneous booster. The polymer types of the microparticles had effects on both IgG and IgA levels. This study provided insights into the design of microparticles of influenza vaccine for subcutaneous administration followed by an unlimited oral boosting, which will have high cost-effectiveness and patient compliance.

Animals↗
PubMed1997

Development of a capillary electrophoretic method for the separation of the macrolide antibiotics, erythromycin, josamycin and oleandomycin.

Capillary electrophoresis (CE) provides high separation efficiency and thus is suitable for the analysis of complex mixtures of structurally similar compounds. The versatile nature of CE can be realised by controlling the chemistry of the inner capillary wall, by modifying the electrolyte composition and by altering the physicochemical properties of the analyte. A CE method has been developed for the separation of three macrolide antibiotics, erythromycin, oleandomycin and josamycin. A systematic approach was used to maximise analyte differential electrophoretic mobility by manipulating electrolyte pH, molarity and composition. In addition, some instrumental parameters such as capillary length and diameter and applied voltage were varied. The effect of the sample solvent and on-capillary concentrating techniques such as field amplified sample injection were investigated. Also, the influence of the injection of a water plug on the quantity of sample injected was demonstrated. The macrolides were completely resolved in less than 30 min in a 100 cm x 75 microm I.D. fused-silica uncoated capillary with a Z-shaped flow cell of path-length 3 mm. The analysis was performed in a 75 mM phosphate buffer (pH 7.5) with 50% (v/v) methanol and an applied voltage of 25 kV was selected to effect the separation.

Anti-Bacterial Agents↗
PubMed1990

Pharmacokinetic evaluation of conventional and controlled release dosage form of propranolol.

A comparative pharmacokinetic study of a new controlled release multiple unit propranolol formulation and a conventional propranolol tablet was carried out in twelve healthy human volunteers in a randomized balanced crossover design. Under a single dosage regimen, subjects were administered either a single capsule containing controlled release propranolol equivalent to 160 mg of the drug or 80 mg of conventional propranolol tablet, twelve hourly. Peak plasma propranolol concentrations were low which occurred later after controlled release administration than after the administration of the conventional tablet. Analysis of the area under the plasma concentration-time curve (AUC) for the two formulations indicate no significant difference of bioavailability despite a prolonged absorption time and maintenance of effective plasma concentration for the controlled release preparation.

Adult↗
PubMedDate not supplied

Physicochemical characterization of influenza viral vaccine loaded surfactant vesicles.

The goal of this study was to develop nonionic surfactant vesicles of influenza antigen for nasal mucosal delivery. The study describes the encapsulation of viral influenza vaccine antigen in nonionic surfactant vesicles using dehydration-rehydration technique and investigation of the influence of the varying proportion of surfactant, cholesterol, and dicetyl phosphate on the morphology, particle size, entrapment efficiency, and in vitro antigen release from surfactant vesicles. The stability of the antigen was studied using SDS-polyacrylamide gel electrophoresis and immunoblotting. The effect of cholesterol concentration and the method of lyophilization on antigen loading and in vitro release of antigen from surfactant vesicles also were studied.

Administration, Intranasal↗
PubMedDate not supplied

Interference of thimerosal in the bicinchoninic acid protein microassay.

In this investigation the total amount of protein present in the three influenza vaccine formulations Fluvirin, Fluzone and Flushield have been tested where thimerosal is present as a preservative. Interaction of thimerosal with protein has been confirmed by analysing ovalbumin as a control against ovalbumin-thimerosal solution. The results indicate that interference of thimerosal can be overcame for the quantitative assay of proteins by BCA technique with the good reproducibility. The present study identified also the degree of interference of thimerosal in the protein formulations and development of a method to nullify the interference by removing thimerosal.

Drug Contamination↗