Sensitive high-performance liquid chromatographic method for procaterol in human urine

Relationship Between Geometric and Aerodynamic Particle Size Distributions in the Formulation of Solution and Suspension Metered-Dose Inhalers

The relationship between the geometric particle size distribution (GPSD) and the aerodynamic particle size distribution (APSD) of commercial solution and suspension metered-dose inhaler (MDI) formulations was assessed to clarify the use of GPSD to estimate the APSD. The size distribution of particles discharged from four suspension and four solution MDIs was measured using the Inas®100 light-scattering spectrometer and a Next Generation Impactor. The conversion factor was calculated by measuring the GPSD and APSD of MDIs. The morphology and physical properties of MDIs were studied using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Six of the eight MDIs showed similar conversion factor profiles, irrespective of their composition and formulation types. Applying the conversion factor obtained from one of the six MDIs resulted in a particle size distribution comparable to each APSD except for some formulations. The two other solution MDIs, which contained citric acid, had much higher and variable conversion factors. SEM images and DSC scans of the solids obtained by nebulization of the solutions containing beclomethasone and/or citric acid showed the formation of a paste-like amorphous solid. These results indicated that APSD of solution and suspension MDIs that form rigid particles may be estimated by using the conversion factor and GPSD. Contrarily, the estimation is more difficult in formulations that tend to lose the particle structure during the measurement.

Production of an Extremly Low Dose Procaterol HCl Preparation by Fluidized-Bed Coating Method: In Vitro and In Vivo Evaluation

A convenient and reliable method to prepare procaterol HCl oral dosage form at an extremely low dosage (25 microg/cap) is presented in this paper. Procaterol HCl was mixed with the film-forming agent hydroxypropyl methylcellulose in an aqueous solution, which was then spray-coated on sugar spheres (Nu-pareil PG 20/25) to produce procaterol HCl pellets. The IR spectra of coated and noncoated pellets indicated that procaterol HCl was coated on the sugar spheres successfully with a weight increment less than 1%. Most of the coated pellets were able to pass through an 18-mesh screen with no agglomeration. The average weights of coated pellets filled inside of capsules were monitored during the filling process. A simple liquid chromatographic method was developed and validated for the assay and uniformity test of procaterol HCl in different dosage forms. The results of assay and content uniformity test for both in-house product and a commercial product, i.e., Meptin-mini tablet, were satisfied. The data of f(2) function and ANOVA analysis for the dissolution profiles of both procaterol HCl products suggested that they are pharmaceutical equivalent. In an in vivo study (n = 24), a single dose of 75 microg procaterol HCl was administrated to each volunteer and the plasma concentration of procaterol was determined by a LC/MS/MS method, developed by the same authors. There were no significant differences (p > 0.05) in the data of AUC(0-->16 h), AUC(0-->infinity), C(max), and MRT for both preparations. It is confirmed that the pellets capsule produced in this study is bioequivalent with Meptin-mini tablet.

Determination of alentamol hydrobromide, a novel antipsychotic agent, in human blood plasma and urine by high-performance liquid chromatography with fluorescence detection and solid-phase extraction

Alentamol hydrobromide, (+)-2-(dipropylamino)-2,3-dihydro-1H-phenalen-5-ol monohydrobromide, is a selective dopamine agonist currently being investigated for the treatment of schizophrenia. This paper describes a reversed-phase high-performance liquid chromatographic-based method for the quantification of alentamol in blood plasma and urine. The method utilizes solid-phase extraction with carboxylic acid-derivatized silica columns. A limit of quantitation of 0.1 ng/ml in plasma was achieved by virtue of selective extraction and fluorescence detection. Example chromatograms of plasma and urine specimens from clinical trials demonstrate the utility of the method.