Delivery Efficiency (delivery + efficiency)

Distribution by Scientific Domains


Selected Abstracts


Colon Delivery Efficiencies of Intestinal Pressure-controlled Colon Delivery Capsules Prepared by a Coating Machine in Human Subjects

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2000
ZHAOPENG HU
Large quantities of pressure-controlled colon delivery capsules (PCDCs) were prepared by a Hicoater-mini pharmaceutical coating machine and colon delivery efficiencies were evaluated in man. Caffeine powder as a model drug was suspended with a polyethylene glycol (PEG) 1000 suppository base at 50°C, and was hardened in no. 0- and no. 2-sized capsular shapes. The capsule-shaped suppositories were coated with 5% w/v ethanolic ethylcellulose (7G grade) solution using the coating machine. By increasing the coating weight of ethylcellulose from 28.6 ± 1.1 mg to 45.3 ± 0.2 mg, the mean coating thickness of no. 0 PCDCs increased from 56 ± 1 ,m to 64 ± 1 ,m. With no. 2 PCDCs, the mean coating thickness increased from 50 ± 1 ,m to 57 ± 1 ,m by increasing the coating weight of ethylcellulose from 8.1 ± 0.5 mg to 11.2 ± 0.3 mg. The no. 0 PCDCs, having a mean ethylcellulose coating membrane thicknesses of 56± 1 ,m (type 1) and 64 ± 1 ,m (type 2), as well as no. 2 PCDCs, having thicknesses of 50 ± 1 ,m (type 3) and 57 ± 1 ,m (type 4), were used for in-vivo evaluation in man. After oral administration of test preparations containing 75 mg of caffeine, saliva samples were obtained and salivary caffeine levels were measured by an HPLC method. The first appearance time, Ti, of caffeine in the saliva was used as a parameter for the estimation of the release time of caffeine from PCDCs in the gastrointestinal tract. The mean Ti values of no. 0 PCDCs were 3.3 ± 0.3 h for type-1 and 5.3 ± 0.3 h for type-2 preparations while the mean Ti values of no. 2 PCDCs were 4.3 ± 0.5 h for type 3 and 5.3 ± 0.3 h for type 4. There were good correlations between ethylcellulose coating membrane thicknesses and in-vivo Ti values. A colon arrival time of 5 h was reported in our subjects by gastrointestinal magnetomarkergraphy. PCDCs having a mean coating thickness of 64± 1 ,m for no. 0 capsules and of 57 ± 1 ,m for no. 2 capsules were thought to deliver caffeine to the human colon efficiently. [source]


Improving Gene Delivery Efficiency of Bioreducible Poly(amidoamine)s via Grafting with Dendritic Poly(amidoamine)s

MACROMOLECULAR BIOSCIENCE, Issue 4 2010
Ya-Nan Xue
Abstract Dendritic poly(amidoamine)s (PAMAM)s were introduced into the side chains of disulfide-containing poly(amidoamine)s via repetitive Michael addition and amidation. The bioreducible poly(amidoamine)s grafted with dendritic polyamidoamines showed high buffer capacity, low cytotoxicity and strong DNA binding ability at low N/P ratio. They were able to condense DNA into small sized polycation/DNA complexes, which degraded and released the incorporated DNA under reductive conditions. In comparison to the original disulfide-containing poly(amidoamine) with aminoethyl side chain, the grafting of the bioreducible poly(amidoamine) with dendrimer greatly improved the transfection efficiencies of 293T and HeLa cells with foreign DNA at various N/P ratios. The structure,gene delivery property relations of dendrimer-grafted polycations will provide valuable insight into the design of highly efficient and less toxic polycationic gene carriers. [source]


East,west: does it make a difference to hospital efficiencies in Ukraine?

HEALTH ECONOMICS, Issue 11 2006
Anatoly I. Pilyavsky
Abstract Ukraine's history has given it a split personality (e.g. divergent cultural influences on economic and managerial behavior), as was observed in the recent political developments both prior to and following the December 2004 elections. Eastern regions were heavily influenced by Russo-Soviet rule, while western regions have more of a European outlook. This study, which is largely exploratory, compares recent trends in hospital efficiency in Ukraine to see if this split personality manifests itself in differential rates of improvement. Given the inflexibility of Soviet-style planned economies, it is hypothesized that western regions will show greater improvement in economic efficiency that can be attributed to higher levels of managerial and medical entrepreneurship. Data for this study comes from three oblasts (i.e. geopolitical regions), one in the west and two in the east, spanning from 1997 to 2001. Data envelopment analysis (DEA) was used to estimate technical efficiency for the hospitals. After correcting for bias, a second,stage Tobit regression was estimated. Results indicate that hospitals in the west improved efficiencies, while those in the east stayed constant. These western areas of the nation, being more amenable to western management and medical ,business' practice, may be quicker to pick up on new techniques to increase healthcare delivery efficiencies. This may stem from the more limited effects of a shorter history of incorporation into a Soviet-style planned and controlled economy in which individual decision-making and entrepreneurship was suppressed in favor of central decision-making by the state. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Colon Delivery Efficiencies of Intestinal Pressure-controlled Colon Delivery Capsules Prepared by a Coating Machine in Human Subjects

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2000
ZHAOPENG HU
Large quantities of pressure-controlled colon delivery capsules (PCDCs) were prepared by a Hicoater-mini pharmaceutical coating machine and colon delivery efficiencies were evaluated in man. Caffeine powder as a model drug was suspended with a polyethylene glycol (PEG) 1000 suppository base at 50°C, and was hardened in no. 0- and no. 2-sized capsular shapes. The capsule-shaped suppositories were coated with 5% w/v ethanolic ethylcellulose (7G grade) solution using the coating machine. By increasing the coating weight of ethylcellulose from 28.6 ± 1.1 mg to 45.3 ± 0.2 mg, the mean coating thickness of no. 0 PCDCs increased from 56 ± 1 ,m to 64 ± 1 ,m. With no. 2 PCDCs, the mean coating thickness increased from 50 ± 1 ,m to 57 ± 1 ,m by increasing the coating weight of ethylcellulose from 8.1 ± 0.5 mg to 11.2 ± 0.3 mg. The no. 0 PCDCs, having a mean ethylcellulose coating membrane thicknesses of 56± 1 ,m (type 1) and 64 ± 1 ,m (type 2), as well as no. 2 PCDCs, having thicknesses of 50 ± 1 ,m (type 3) and 57 ± 1 ,m (type 4), were used for in-vivo evaluation in man. After oral administration of test preparations containing 75 mg of caffeine, saliva samples were obtained and salivary caffeine levels were measured by an HPLC method. The first appearance time, Ti, of caffeine in the saliva was used as a parameter for the estimation of the release time of caffeine from PCDCs in the gastrointestinal tract. The mean Ti values of no. 0 PCDCs were 3.3 ± 0.3 h for type-1 and 5.3 ± 0.3 h for type-2 preparations while the mean Ti values of no. 2 PCDCs were 4.3 ± 0.5 h for type 3 and 5.3 ± 0.3 h for type 4. There were good correlations between ethylcellulose coating membrane thicknesses and in-vivo Ti values. A colon arrival time of 5 h was reported in our subjects by gastrointestinal magnetomarkergraphy. PCDCs having a mean coating thickness of 64± 1 ,m for no. 0 capsules and of 57 ± 1 ,m for no. 2 capsules were thought to deliver caffeine to the human colon efficiently. [source]


Nanogold-Loaded Sharp-Edged Carbon Bullets as Plant-Gene Carriers

ADVANCED FUNCTIONAL MATERIALS, Issue 15 2010
Periyasamy S. Vijayakumar
Abstract The higher DNA delivery efficiency into plants by gold nanoparticles embedded in sharp carbonaceous carriers is demonstrated. These nanogold-embedded carbon matrices are prepared by heat treatment of biogenic intracellular gold nanoparticles. The DNA-delivery efficiency is tested on a model plant, Nicotiana tabacum, and is further extended to the monocot, Oryza sativa, and a hard dicot tree species, Leucaena leucocephala. These materials reveal good dispersion of the transport material, producing a greater number of GUS foci per unit area. The added advantages of the composite carrier are the lower plasmid and gold requirements. Plant-cell damage with the carbon-supported particles is very minimal and can be gauged from the increased plant regeneration and transformation efficiency compared with that of the commercial micrometer-sized gold particles. This is ascribed to the sharp edges that the carbon supports possess, which lead to better piercing capabilities with minimum damage. [source]


Scintigraphy can be used to compare delivery of sore throat formulations

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 4 2009
M. Limb
Summary Aims:, Sore throat (pharyngitis) is commonly treated with over-the-counter lozenges, tablets, sprays and gargles. While the efficacy of the active ingredients has been examined, less is known about the comparative efficacy of the different delivery formats. Methods:, A pilot study was initially performed, followed by an open-label, four-way crossover study in healthy volunteers to quantitatively assess the delivery efficacy of a lozenge, tablet, spray and gargle, using technetium-99m and scintigraphy as a marker of deposition and clearance of the active ingredients. Results:, Initial deposition in the mouth and throat combined was significantly greater for the solid dose forms (lozenge and tablet) than for the spray or gargle. Rates of clearance were initially similar for the tablet and lozenge with low levels of radioactivity present at up to 2 h. At 10 and 20 min, significantly more of the dose remained for the lozenge than for the tablet. The mouth appeared to act as a reservoir for continued clearance to the throat. Discussion and Conclusion:, Scintigraphy is an effective means of quantifying the delivery efficiency, and hence availability, of sore throat medications. The results presented here suggest that both lozenges and tablets offer considerable advantages over sprays or gargles, both in terms of proportion of the dose delivered to the mouth and throat, combined, and clearance from these regions. These delivery formats provide fast, effective and prolonged delivery of active ingredients, highlighting their potential benefits for sore throat medication. [source]


Skin permeation of retinol in Tween 20-based deformable liposomes: in-vitro evaluation in human skin and keratinocyte models

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2006
Yu-Kyoung Oh
To develop a more effective transdermal delivery method for lipophilic functional cosmetic compounds such as retinol, we formulated various deformable liposomes and compared their transdermal delivery efficiency with those of neutral or negatively-charged conventional liposomes. We tested the deformability of liposomes containing edge activators such as bile salts, polyoxyethylene esters and polyoxyethylene ethers. As indicators of deformability, we used the passed volume and phospholipid ratios during extrusion, as well as the deformability index. We found that the type of edge activator significantly affected the extent of deformability, and that Tween 20 provided the highest level of deformability. Accordingly, we used Tween 20 to formulate deformable liposomes containing retinol in the membrane bilayers, and conducted a skin permeation study in Franz diffusion cells, using dermatomed human skin and three-dimensional human keratinocyte layers. As compared with the use of conventional neutral or negatively-charged liposomes, the use of Tween 20-based deformable liposomes significantly increased the skin permeation of retinol. These results suggested that deformable liposomes might be of potential use for the formulation of retinol and other lipophilic functional cosmetic compounds. [source]


The science of aerosol delivery in cystic fibrosis

PEDIATRIC PULMONOLOGY, Issue S9 2008
David E. Geller MD
Abstract Aerosolized drugs are universally used for treatment of cystic fibrosis airway disease. Inhalation can increase topical efficacy and reduce systemic exposure and toxicity of many drugs. A wide variety of inhaled drugs already exist with many more in the therapeutic pipeline. Understanding the principles of aerosol delivery and how aerosol devices function is important in designing the best therapeutic regimens for CF patients. The variables that determine where an aerosol deposits are numerous and complex. Important aerosol-related variables include particle-size distribution, hygroscopic properties, viscosity and surface tension of the drug. Patient-related variables include inspired flow rate, tidal volume, respiratory rate, breath-holding, upper airway anatomy, lower airways obstruction, and the cognitive and physical ability to use the device. These factors vary widely between patients of different age groups and disease severities, and cause the high variability in drug delivery seen with aerosol drugs. Classic aerosol delivery devices like metered dose inhalers and dry-powder inhalers are small, portable, and have short treatment times. However, they are limited by small drug payloads and user technique problems. Jet nebulizers are commonly used for CF drugs, are easy to operate, require no special breathing pattern, and can deliver very large quantities of drug. However, they require a power or air source, cleaning and sanitizing, and are relatively time consuming. Recently, novel aerosol delivery systems and formulations have been developed to improve delivery efficiency and reduce variability and delivery time. These new systems can ease the treatment burden and improve adherence and outcomes in cystic fibrosis. Pediatr Pulmonol. 2008; 43:S5,S17. © 2008 Wiley-Liss, Inc. [source]


Tumor hypoxia: A target for selective cancer therapy

CANCER SCIENCE, Issue 12 2003
Shinae Kizaka-Kondoh
Tumor hypoxia has been considered to be a potential therapeutic problem because it renders solid tumors more resistant to sparsely ionizing radiation (IR) and chemotherapeutic drugs. Moreover, recent laboratory and clinical data have shown that tumor hypoxia is also associated with a more malignant phenotype and poor survival in patients suffering from various solid tumors. Therefore, selective targeting of hypoxic tumor cells has been explored, and since severe hypoxia (pO2<0.33%, 2.5 mmHg) does not occur in normal tissue, tumor hypoxia could be exploited for therapeutic advantage. However, the following three characteristics of hypoxic tumor regions present obstacles in targeting hypoxic cells. First, it is difficult to deliver a sufficient amount of drug to a region that is remote from blood vessels. Second, one must specifically target hypoxic tumor cells while sparing normal well-oxygenated tissue from damage. Finally, the severely hypoxic tumor cells to be attacked have often stopped dividing. Therefore, high delivery efficiency, high specificity and selective cytotoxicity are all necessary to target and combat hypoxic tumor cells. The current review describes progress on the biological aspects of tumor hypoxia and provides a compilation of the recent molecular approaches used to target hypoxic tumors. These approaches include our work with a unique hypoxia-targeting protein drug, TOP3, with which we have sought to address the above three difficulties. [source]