Pharmaceutical Research
1573-904X
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Các bài báo tiêu biểu
Development of a Remote Electrode System for Monitoring the Water Content of Materials Inside a Glass Vial
Tập 19 Số 3 - Trang 337-344 - 2002
Purpose: This article explores the use of a remote electrode dielectric measurement system to monitor the water content of hydrated ovalbumin inside a glass vial. Methods: The intrinsic dielectric properties of hydrated ovalbumin were characterized first using conventional parallel plate electrodes. The second stage was to simulate a remote electrode measurement by placing nonconductive, nondisper......
Determination of the Origin of Charge Heterogeneity in a Murine Monoclonal Antibody
Tập 17 Số 9 - Trang 1110-1117 - 2000
Purpose. The aim of this study was to elucidate the molecular basis of charge heterogeneity found in a purified monoclonal IgG1 antibody, MMA383. Methods. Cation exchange chromatography (CEX) and isoelectric focusing (IEF) were used to monitor charge heterogeneity. CEX in conjunction with carboxypeptidase B digests of the antibody was used to determine the contribution of C-terminal lysines to MMA......
Spectroscopic Characterization of Interactions Between PVP and Indomethacin in Amorphous Molecular Dispersions
Tập 14 Số 12 - Trang 1691-1698 - 1997
Purpose. To study the molecular structure of indomethacin-PVP amorphous solid dispersions and identify any specific interactions between the components using vibrational spectroscopy. Methods. Solid dispersions of PVP and indomethacin were prepared using a solvent evaporation technique and IR and FT-Raman spectra were obtained. Results. A comparison of the carbonyl stretching region of γ indometha......
Uptake of FITC-Chitosan Nanoparticles by A549 Cells
Tập 19 Số 10 - Trang 1488-1494 - 2002
Purpose. The objective of this study was to evaluate the extent and mechanism of uptake of fluorescent chitosan nanoparticles by the A549 cells, a human cell line derived from the respiratory epithelium. Methods. Covalent conjugation with fluorescein-5-isothiocyanate yielded stably labeled chitosan molecules, which were successfully formulated into nanoparticles by ionotropic gelation. Uptake of f......
A Solid-State NMR Study of Protein Hydration and Stability
Tập 15 Số 12 - Trang 1816-1821 - 1998
Purpose. The mobility of protein in powders at different hydration levels was studied in relation to aggregation and activity. Methods. Magic angle spinning 13C, 15N, 1H, 2H, and 17O NMR techniques were used to determine changes in the mobility of surface residues in proteins as a function of hydration and related to changes in activity. NMR relaxation measurements of high frequency (ω0, T1) and l......
Cationic Polymer Based Gene Delivery Systems
Tập 17 Số 2 - Trang 113-126 - 2000
Gene transfer to humans requires carriers for the plasmid DNA which canefficiently and safely carrythe gene into the nucleus of the desired cells. A series of chemically differentcationic polymers arecurrently being investigated for these purposes. Although many cationic polymersindeed condense DNAspontaneously, which is a requirement for gene transfer in most types of cells,the physicochemical an......
Protein–Solvent Interactions in Pharmaceutical Formulations
Tập 8 Số 3 - Trang 285-291 - 1991
The stability of proteins is affected by a variety of solvent additives. Sugars, certain amino acids and salts, and polyhydric alcohols stabilize proteins in solution and during freeze-thawing. Urea and guanidine hydrochloride destabilize proteins under either condition. These effects can be explained from the preferential interactions of the cosolvents with the proteins; i.e., the protein stabili......
Development of New Lipophilic Derivatives of Tetragastrin: Physicochemical Characteristics and Intestinal Absorption of Acyl-tetragastrin Derivatives in Rats
Tập 10 Số 10 - Trang 1488-1492 - 1993
In order to improve the intestinal absorption of tetragastrin (TG), we synthesized lipophilic derivatives of TG by acylation of its N-terminal amino group with acetic acid, caproic acid, and lauric acid. The purified TG derivatives, acetyl-tetragastrin (Ac-TG), caproyl-tetragastrin (Cap-TG), and lauroyl-tetragastrin (Lau-TG), were confirmed to be more lipophilic than the parent TG by high-performa......
The Stability of Insulin in Crystalline and Amorphous Solids: Observation of Greater Stability for the Amorphous Form
Tập 14 Số 10 - Trang 1379-1387 - 1997
Purpose. Generalizations based upon behavior of small molecules have established that a crystalline solid is generally much more stable toward chemical degradation than is the amorphous solid. This study examines the validity of this generalization for proteins using biosynthetic human insulin as the model protein. Methods. Amorphous insulin was prepared by freeze drying the supernate from a suspe......
Mucoadhesive Polymers in Peroral Peptide Drug Delivery. II. Carbomer and Polycarbophil Are Potent Inhibitors of the Intestinal Proteolytic Enzyme Trypsin
Tập 12 Số 9 - Trang 1293-1298 - 1995
Purpose. The evaluation of the inhibitory action of two mucoadhesive poly(acrylates), polycarbophil and carbomer, registered by the Food and Drug Administration (FDA), on the intestinal proteolytic enzyme trypsin. Methods. The effect of the polymers on trypsin activity by measuring the degradation of a trypsin specific substrate. Binding of Ca2+ ions and proteins (125I-BSA) to the poly(acrylates).......