Immunopharmacological activity of Echinacea preparations following simulated digestion on murine macrophages and human peripheral blood mononuclear cells.
We have investigated the immunostimulatory, anti-inflammatory, and antioxidant activities of various Echinacea raw materials and commercially available products on murine macrophages and human peripheral blood mononuclear cells (PBMCs). To emulate oral dosing, a simulated digestion protocol was employed as a means of sample preparation. Echinacea-induced macrophage activation was used as a measure of immunostimulatory activity determined via quantitative assays for macrophage-derived factors including tumor necrosis factor alpha, interleukin (IL)-1alpha, IL-1beta, IL-6, IL-10, and nitric oxide. Echinacea herb and root powders were found to stimulate murine macrophage cytokine secretion as well as to significantly enhance the viability and/or proliferation of human PBMCs in vitro. In contrast, Echinacea extracts chemically standardized to phenolic acid or echinacoside content and fresh pressed juice preparations were found to be inactive as immunostimulatory agents but did display, to varying degrees, anti-inflammatory and antioxidant properties. (+info)
Bioavailability study of oral liquid and tablet forms of alpha-difluoromethylornithine.
The purpose of this study was to assess the bioavailability of two oral preparations of difluoromethylornithine (DFMO). The current preparation of DFMO is a liquid with a concentration of 0.2 gram/ml that must be drawn up into a syringe and dispensed into a small medicine glass. This form of DFMO causes wastage of the medication. The liquid form also makes compliance and blinding difficult. Recently, a new coated tablet preparation has become available from Ilex Oncology Services (San Antonio, TX). The coated tablets are 0.25 gram and are scored. The tablet form should increase compliance by making it much easier for the subject to take the medication. This report compares the bioavailability of both preparations with the goal of demonstrating equivalence of the preparations. Ten normal subjects entered the cross-over study in which the order in which they would receive the liquid or tablet preparation of DFMO was randomized. The study was designed with the objective of establishing the bioequivalence of a tablet preparation of DFMO at daily dose 0.5 gram/m2 and a liquid preparation of DFMO at the same daily dose. The mean area under the time-by-concentration curves (microM x hours) for the liquid and tablet preparations was 368.2 and 370.4, respectively. The peak concentrations for the liquid and tablet preparations were 47.3 and 48.2 microM, respectively. No statistically significant differences were seen in these parameters, in time to peak concentration, or in serum half-life. (+info)
Pulsepolarographic determination of 6-benzyl-2-thio-uracil.
Polarographic (DPP) activity of 6-benzyl-2-thiouracil (6-benzyl-2-mercapto-4-pyrimidinol, BTU) has been examined in a wide range of pH values and it has been discovered that the number and the height of observed peaks depends on composition of supporting electrolyte and concentration of the thiol. Two different types of signals can be obtained. One of them is controlled by diffusion while the other by adsorption. The procedure for the determination of BTU in pure samples in 0.1 mol.dm-3 sodium hydroxide solution has been worked out. The measurements can be performed in a range 3.10(-4)-3.10(-3) mol.dm-3 of BTU. The detection limit is however lower and reaches 5.10(-6) mol.dm-3. The method has been used in the determination of BTU in an antithyroid drug Basdene. (+info)
The use of HPLC method for determination of the folic acid in multi-component vitamin preparations.
In the present study we tried to use HPLC method to determine the folic acid content in multivitamin and multimineral pharmaceutical preparations. The reverse phases technique was applied and measurements were made at the wavelength 282 nm. The elaborated method, because of its sufficient precision, accuracy as well as short time retention of folic acid may be used as an alternative method to microbiological. (+info)
Dissolution properties of different designed and formulated salbutamol tablet dosage forms.
Pharmaceutical availability or in vitro availability is one of the aspects of drug bioavailability. Dissolution can be described best as a tool that can provide valuable information about the availability of a drug product. Dissolution test was performed on three different designed and formulated of salbutamol tablet formulations marketed in Turkey. The test methods were the paddle method and the rotating basket method described in United States Pharmacopeia. All studied formulations showed a good agreement with pharmacopeial requirements. In particular all studied commercial tablet formulations showed a quite fast release of the antiasthmatic drug. Other type of table formulations showed slow release. In order to evaluate the dissolution rates five different kinetics have been examined and the best fitting kinetics was found to be RRSBW kinetic. (+info)
The consolidation and compressibility properties of some novel directly compressible filler-binders.
The aim of this study was to investigate the consolidation and compressibility properties and also the dilution potentials of some novel directly compressible filler-binders. For this purpose, Ludipress and Cellastose 80 (one-body compounds), Tablettose 70 and Tablettose 80 (alpha-mono agglomerated lactose) were selected. They were diluted at predetermined percentages with Spherolac 100 which is a coarse sieved hydrous crystalline lactose. The consolidation and compressibility properties of the prepared powder mixtures were determined. The experimental data were evaluated by using a computer programme (Basic 80). (+info)
Determination of cetirizine dichloride in tablets by HPLC method.
A HPLC method for the determination of the cetirizine dichloride in tablets was developed and validated. The determination was performed with a LiChrosorb RP-18 column, mobile phase of KH2PO4 (0.01 mol/l)--acetonitrile 65:35 (v/v), flow rate: 2 ml.min-1, UV detection at 230 nm and methyl paraben as an internal standard. (+info)
Effects of membrane composition on release of model hydrophilic compound from osmotic delivery systems.
In this study, the effects of surface-active agents in different types and concentrations, added into the coating solution, on release of model hydrophilic compound have been examined. For this purpose, the tablets, prepared with the use of methylene blue as a model substance, were coated by spray coating technique with cellulose acetate solution containing polyethylene glycol 400 as a plasticizer. In addition, cetylpyridinium chloride as cationic surface-active agent and sodium lauryl sulphate as anionic surface-active agent were added into coating solution in different concentrations. After creating a delivery orifice by a microdrill on the tablets, release of model hydrophilic compound was tested by the USP paddle method. The data obtained were evaluated according to the different kinetics and the mechanism of release from the preparations was examined. The surface properties of the coating material were investigated by scanning electron microscope taken before and after the contact with medium fluid, as well as the mechanical properties by tensile tests. In conclusion, it has been found that the cationic surface active agent, cetylpyridinium chloride reduced the lag time, observed during the release of model hydrophilic compound, as a result of its enhancing effect on wettability of tablets by reducing the contact angle between the medium fluid and the coating material. On the other hand, the anionic surface active agent, sodium lauryl sulphate has been inactivated possibly due to the interaction with model hydrophilic compound that has cationic properties and/or substances contained in membrane composition; thus, the lag time has not decreased and furthermore, a significant decrease in the delivery rate of model hydrophilic compound has been observed. (+info)