Journal of pharmaceutical sciences
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The aim was to investigate if solid drug/cyclodextrin complexes could be produced in a single-step process with a solution enhanced dispersion by supercritical fluids (SEDS) method. Budesonide and gamma-cyclodextrin (CD) solutions (50% or 99.5% ethanol) were pumped from the same (conventional method) or separate (modified method) containers together with supercritical carbon dioxide through a coaxial nozzle into a particle formation chamber. The pressure was maintained at 100, 150 or 200 bar with a temperature of 40, 60 or 80 degrees C. ⋯ For example, with the conventional method (100 bar, 60 degrees C) the yield of the powder was 65+/-12% with 0.14+/-0.02 mg budesonide/mg powder, corresponding to 1:2 drug:CD molar ratio. The dissolution rate of this complexed budesonide (93+/-2% after 15 min) was markedly higher compared to unprocessed micronised budesonide (41+/-10%) and SEDS-processed budesonide without CD (61+/-3%). As a conclusion, SEDS is a novel method to produce solid drug/CD complexes in a single-step process.
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This study was conducted to investigate the effect of reversible protein self-association on the viscosity of concentrated monoclonal antibody solutions. The viscosities of the monoclonal antibody solutions were measured by either a capillary viscometer or a cone-plate rheometer at different protein concentrations, pH, and ionic strength. Soluble aggregates were determined by size exclusion chromatography, light scattering, and analytical ultracentrifugation. ⋯ The self-association appears to be quite weak and is not detectable by sedimentation velocity and size exclusion chromatography at low protein concentration. There are no significant differences in the amounts of non-dissociable soluble aggregates formed between low viscosity and high viscosity samples. These results suggest that the reversible multivalent self-association of this protein appears to be mediated mainly by electrostatic interactions of charged residues and results in unusually high viscosity of this monoclonal antibody in solution at low ionic strength conditions.
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The hepatic distribution, biliary excretion, and mass balance of liposomal amphotericin B (L-AmB) were investigated in recirculated isolated perfused rat liver. The results were compared with those from the conventional AmB formulation, amphotericin B deoxycholate (D-AmB). L-AmB was introduced as a bolus into the perfusate reservoir, at doses of 1000, 4000, and 8000 mug, to achieve therapeutically relevant concentrations. ⋯ Hepatic uptake clearance of L-AmB (CL(H,uptake)) decreased with the increase in perfusate area under the curve at each dose. The relationship between perfusate area under the curve and CL(H,uptake) was described by a parallel hepatic uptake clearance model. In conclusion, liposomal encapsulation significantly alters the hepatobiliary disposition of AmB; the ability of liposomes to sequester AmB and the dose-dependent hepatic uptake clearance may account for dose-form-dependent differences in AmB pharmacokinetics.
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Comparative Study
In vitro and in vivo evaluation of a sulfobutyl ether beta-cyclodextrin enabled etomidate formulation.
In this study, we report the formulation and in vivo evaluation of etomidate in an aqueous solution using sulfobutyl ether-7 beta-cyclodextrin (SBE-CD, Captisol) as a solubilizing agent. The phase-solubility behavior of etomidate as a function of SBE-CD concentration was evaluated, and accelerated solution stability studies of 2 mg/mL etomidate in a 5% w/v SBE-CD solution were conducted. The intravenous administration of the SBE-CD etomidate formulation in dogs was compared with Amidate, the commercial etomidate drug product formulated with propylene glycol as a cosolvent. ⋯ In vivo hemolysis after intravenous administration of Amidate was 10-fold higher than the SBE-CD formulation. Whereas Amidate cannot be given subcutaneously because of the cosolvent in the formulation, a 12 mg/mL aqueous solution of etomidate in 20% (w/v) SBE-CD was well tolerated by this route. The results suggest that the SBE-CD formulation is a viable clinical drug product with a reduced side-effect profile.
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Randomized Controlled Trial Comparative Study Clinical Trial
Development and pharmacokinetic characterization of pulmonal and intravenous delta-9-tetrahydrocannabinol (THC) in humans.
The aim of the present study was to develop a physiologically compatible inhalation solution of delta-9-tetrahydrocannabinol (THC), and to compare the pharmacokinetic and analgesic properties of pulmonal THC versus pulmonal placebo and intravenous (iv) THC, respectively. Eight healthy volunteers were included in this randomized, double-blind, crossover study. The aqueous THC formulations were prepared by using a solubilization technique. iv THC (0.053 mg/kg body weight), pulmonal THC (0.053 mg/kg), or a placebo inhalation solution was administered as single dose. ⋯ The side effects observed after pulmonal THC were coughing and slight irritation of the upper respiratory tract, very mild psychotropic symptoms, and headache. The side effects after iv THC were much more prominent. Neither pulmonal nor iv THC significantly reduced experimentally induced pain.