Showing papers in "Journal of Pharmaceutical Sciences in 1999"

TL;DR: Commercial use of solid dispersion systems during the past four decades has been very limited, primarily because of manufacturing difficulties and stability problems, but this has been changing in recent years because of the availability of surface-active and self-emulsifying carriers and the development of technologies to encapsulate solid dispersions directly into hard gelatin capsules as melts.

TL;DR: Investigation of MDCK (Madin-Darby canine kidney) cells as a possible tool for assessing the membrane permeability properties of early drug discovery compounds indicates that M DCK cells may be a useful tool for rapid membrane permeable screening.

TL;DR: It was concluded that Hildebrand parameters give an indication of possible incompatibilities between drugs and carriers in solid dispersions, but that the use of partial solubility parameters may provide a more accurate prediction of interactions in and between materials and could provide more accurate indications of potential incomp atibilities.

TL;DR: It is shown that consideration of only a single conformer when computing PSA gives an excellent correlation with intestinal absorption data-as good as previously reported methods employing multiple conformers.

TL;DR: The derivation of a simple QSAR model that permits the prediction of log BB for large compound sets, such as virtual combinatorial libraries, from a set of 55 diverse organic compounds is described.

TL;DR: P pH-responsive, poly(methacrylic-g-ethylene glycol) hydrogels are investigated as oral delivery vehicles for insulin to protect the sensitive drug from proteolytic degradation in the stomach and upper portion of the small intestine.

TL;DR: The illusion of process control is motivated by a crystallization process that yields the desired productssolid phase modification, shape, or size distributions by the robust analytical methods used for solid state characterization.

TL;DR: It is hypothesized that freezing the aqueous phase of the primary emulsion would help to preserve the supercoiled plasmid DNA during formation of the secondary emulsion, and that disruption of the crystal formation by the addition of saccharides into the primaryEmulsion would improve the super coiled-DNA content of the spheres.

TL;DR: The major chemical reactions affecting proteins and peptides in the solid-state are summarized: deamidation, peptide bond cleavage, oxidation, the Maillard reaction, beta-elimination, and dimerization/aggregation.

TL;DR: The aqueous solubility of liquids and solids, as log S(W), has been correlated with an amended solvation equation that incorporates a term in Sigma alpha(2)(H) x Sigma beta( 2)(H), where the latter are the hydrogen bond acidity and basicity of the solutes, respectively.

TL;DR: A novel mathematical model for the water transport into and drug release from hydroxypropyl methylcellulose (HPMC) tablets is presented and it is shown that the diffusion coefficients strongly depend on the water concentration.

TL;DR: Identifying critical formulation and processing variables affecting aggregation of bovine IgG during freeze-drying when no lyoprotective solute is used underscores the importance of minimizing secondary drying of this system.

TL;DR: A drug-excipient compatibility screening model was developed by which potential stability problems due to interactions of drug substances with excipients in solid dosage forms can be predicted and selection of dosage form composition by using this model would lead to reduction of "surprise" problems during long-term stability testing of drug products.

TL;DR: Current knowledge regarding obesity is reviewed ranging from genetic and nutritional animal studies to pharmacokinetic studies of specific drugs in humans to comprehensively review current knowledge regarding Obesity.

TL;DR: It is concluded that nasally administered cocaine was transported directly from the nasal cavity to the brain but that only a very small fraction of the dose was transported via the direct pathway.

TL;DR: It is concluded that highly quaternized TMC is a potent absorption enhancer and the potential use of this polymer, especially in neutral and basic environments where normal chitosan salts are not effective, is expected to be an important contribution to the development of effective delivery systems for hydrophilic compounds such as peptide drugs.

TL;DR: Simulated dissolution data showed that the ratio between particle size and diffusion layer thickness (a0/h) is an important factor in controlling the shape of particle dissolution profiles.

TL;DR: Results indicated that competitive adsorption modes of proteins could be used to stabilize a protein of interest against the denaturing effects of emulsification.

TL;DR: Calculations of spray-droplet formation time and drying time indicate than the extent of diffusion-driven LDH adsorption to the liquid/air interface is sufficient to account for the measured amount of LDH inactivation during spray-drying.

TL;DR: The mannitol hydrate showed a distinct X-ray powder diffraction pattern, low melting point, and steplike desolvation behavior that is characteristic of crystalline hydrates, and was found to be metastable, converting to anhydrous polymorphs ofMannitol upon heating and exposure to moisture.

TL;DR: Sorbitan monostearate, a hydrophobic nonionic surfactant, gels a number of organic solvents such as hexadecane, isopropyl myristate, and a range of vegetable oils.

TL;DR: The ability of surface-coated liposomes, especially of PEG-Lip, to interact with the mucus layer and slow the transit rate in the GI tract is considered desirable for oral delivery of peptide drugs.

TL;DR: This process offers a means to produce encapsulated proteins in poly(DL-lactide-co-glycolide) microspheres without earlier limitations of massive polymer agglomeration and limited protein solubility in organic solvents.

TL;DR: The deamidation reactions of asparagine residues in alpha-helical and beta-turn secondary structural environments of peptides and proteins are reviewed and simple considerations suggest a stabilization in this environment also.

TL;DR: Compared to analogous liposomal vector preparations lacking an optimally compacted DNA core, a cell-specific targeting ligand, a caged fusogenic lipid, and a nucleotide sequence that facilitates nuclear uptake, these modifiedliposomal vectors display greatly improved transfection efficiencies and target cell specificity.

TL;DR: The permeability of various drugs in Caco-2 monolayers was determined experimentally and modeled using a combination of passive absorptive membrane permeability and a Michaelis-Menten-type transport process in the secretory direction, and a model was presented to quantitatively describe and predict direction-dependent drug fluxes, with differing passive membrane permeabilities and P-glycoprotein affinities.

TL;DR: Microdialysis sampling has several characteristics that complement traditional in vitro and in vivo pharmacokinetic and metabolism techniques, and can be thought of as an artificial blood vessel in that it can both deliver and remove compounds from the local area.

TL;DR: For both the single and multiple dosing of thalidomide, the apparent volume of distribution and half-life were significantly higher for the high- dose group than those for the low-dose group, and a dose-proportional increase in thalidmide steady-state concentrations was seen after multiple daily dosing.

TL;DR: Thermodynamic prediction, thermal analysis, and structural study are in excellent agreement for identifying the nature of the racemic species.