SEARCH · PubMed Health

Results for “delivery systems”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed1978

Simulated respiratory system for in vitro evaluation of two inhalation delivery systems using selected steroids.

A simulated respiratory system was developed for the in vitro evaluation of two differently designed oral inhalation delivery systems. The deposition properties of a newly designed delivery system used for triamcinolone acetonide were compared to the more conventional, commercially available adapter utilized for an aerosol containing beclomethasone dipropionate. The simulated respiratory system was constructed so that the delivered dose of active ingredient could be classified into two fractions: the fraction that would be deposited in the oral cavity and throat and the fraction that would reach the desired site of activity in the respiratory tract. Based on this method, the newly designed system delivered more than 95% of the labeled dose to the desired site. The beclomethasone dipropionate aerosol system, which was observed to discharge the active ingredient with a greater intensity, delivered approximately 40% of the labeled dose. The particle-size distribution of the dose dispensed from the newly designed delivery system attached to the triamcinolone acetonide aerosol was determined using an impactor technique. No effort was made to correlate these results with an in vivo response.

Aerosols↗

PubMed1979

Inadequate removal of methanol and formate using the sorbent based regeneration hemodialysis delivery system.

The sorbent based hemodialysis delivery system was shown to be ineffective for the treatment of methanol intoxication. Clinical and in vitro studies showed rapid saturation of the sorbent cartridge for methanol and formate adsorption. Methanol and formate clearances were four fold less than achieved with the recirculating single pass delivery system. The sorbent delivery system should not be used for methanol intoxication.

Formates↗

PubMed1979

Placebo granules as cores for timed release drug delivery systems.

A drug delivery system is proposed constituted of spherical placebo granules as cores with polymeric surface films containing drug. This timed release dosage form has been prepared by means of a fluidized bed coating technique using ethyl cellulose as the polymeric film and caffeine and salicylic acid as model drugs. The release of the drugs from the dosage form (a) at different drug concentrations and (b) into solutions of different pH showed that drug release was linearly related to the square root of time. Good agreement was found between the theoretical release rate of caffeine, calculated according to Higuchi's equation for a homogenous matrix using membrane permeation parameters measured on linear films, and the experimental results in the case of low drug concentrations. Deviation of the release rate from the homogenous model at high drug concentrations could be explained by crystallization of the drug from the film.

Caffeine↗

PubMed1978

Plasma corticosteroid levels in rats maintained on a long-acting naltrexone delivery system.

A long-acting delivery system for naltrexone has been described, which blocked the antinociceptive action of 10 mg kg-1 s.c. dose of morphine in rats for a period of 2 to 3 months. Male Wistar rats implanted s.c. with such a delivery system showed highly significant depression of plasma corticosteroid levels (40.2% in one week and 22.4 to 27.2% in 3 months) as compared to placebo pellet-implanted animals. Morphine-dependent male rats implanted with 75 mg morphine pellets showed a small (17.5%) but significant increase in plasma corticosteroid levels as compared to the placebo controls 72 hr. after pellet implantation.

Adrenal Cortex Hormones↗

PubMed1977

Psychiatric hospitalization. II. Effect of social class and delivery systems.

The effects of social class and delivery system on admission and behavioral variables, diagnosis, treatment, and length of hospitalization were studied by comparing patients admitted over a one-year period to the psychiatric services of a public and a private general hospital, staffed by the same Department of Psychiatry. Patients were of similar age and sex and were matched by social class. Crisis-precipitated admissions and affective-disorder diagnoses varied with social class irrespective of treatment facility. Patients diagnosed as schizophrenic were more common in the upper classes at the private facility and the lower classes at the public facility. Somatic treatments and length of hospitalization also varied according to social class as well as delivery system. The results of this study imply that economic differences between public and private delivery systems operate to select patients for admission and affect expeditiousness of treatment, perhaps to the detriment of patients in both systems.

Adult↗

PubMed1978

Intangibles facilitating or inhibiting health care delivery systems.

Proponents of general systems theory believed its principles were applicable to a variety of living systems. General systems theory was applied to health care delivery systems and provided a conceptual framework for operation. Intangibles in the health care delivery system may inhibit or facilitate open or closed systems and thereby directly or indirectly influence the quality and quantity of care. This paper reviews and discusses: 1) Basic concepts of general systems theory; 2) Application of general systems theory to health care delivery systems, including the Air Evac system; 3) Intangibles in systems which facilitate or inhibit health care delivery; and 4) Suggestions to facilitate open systems and the delivery of quality care.

Aerospace Medicine↗

PubMed1978

Effectiveness of preventive dentistry delivery system.

A preventive dentistry delivery system was developed for maximum effectiveness in private practice. Four new pit or fissure carious lesions developed in 20 patients who were 10 to 20 years old at the start of a two-year exploratory test; there were no new lesions of smooth surfaces. Of the incipient lesions that were under observation, no increase was observed in 23 of 26 pit or fissure lesions, 24 to 25 proximal and all of 26 buccal or lingual smooth surface lesions. In 33 patients 21 to 30 years old at the start of the test, no new lesions appeared and growth of the 142 incipient lesions appeared to be arrested. A low level of gingivitis was maintained in all patients who were tested.

Acidulated Phosphate Fluoride↗

PubMed1978

A new anesthesia delivery system.

A prototype anesthesia delivery system has been developed to test the appropriateness of new technological design approaches. The objectives were to eliminate human-factors problems associated with present anesthesia apparatus and to lay a suitable technical foundation for the development of new techniques in anesthesia management. This prototype performs all the functions of a conventional anesthesia machine, as well as many monitoring and surveillance tasks. Eventual incorporation of new teaching functions, and additional monitoring and record-keeping activities, are intended. The system is fundamentally electronic with few moving parts. Reliability, safety, and clarity of operation were the primary criteria in selection and application of the specific technologies employed. The result is a promising first step in the development of a system oriented toward supporting rather than preoccupying the anesthestist.

Anesthesia↗

PubMed1978

The single-unit delivery system--a safe alternative to home deliveries.

The need has arisen for the development of a health care/delivery system that can allow for a natural and personalized childbirth experience, within the safe confines of a modern obstetric unit. The single-unit delivery system (SUDS) is designed to achieve this objective by: strict prenatal screening of patients into low- and high-risk categories, utilization of a single room for the entire labor process, and close personalized supervision of women in "normal" labor by trained midwives/monitrixes. Physicians supervise the entire unit and are directly responsible for the management of all high-risk and complicated labors. The SUDS concept has been tried in clinical practice and has been proved to be an effective method of providing safe and satisfying obstetric care without compromising modern obstetric standards.

Delivery, Obstetric↗

PubMed1976

Testing of drug delivery systems for use in the treatment of narcotic addiction.

The evaluation of the drug release characteristic of four naltrexone delivery systems has been carried out together with the development of analytical techniques and an investigation of the metabolic profile of naltrexone. Pharmacologic evaluation of the four delivery systems in the mouse indicated significant analgesic antagonism for a period of from 16-22 days. Further evaluation of one of these systems by measurement of the rate of excretion of radioactivity after administration of radiolabelled naltrexone in the delivery system confirmed that significant release occurs for a time period of about 15 days. Electron capture gas-liquid chromatographic assays for naltrexone and naloxone in plasma or urine have been developed that yield linear calibration curves and are sensitive to one ng/ml. Studies on naltrexone disposition indicate that (a) binding to plasma proteins in several species varies from 20-26%, (b) distribution of drug from blood is extremely rapid and extensive, (c) beta-naltrexol is a major metabolite of naltrexone in man, monkey and guinea pig among six species studies, whereas alpha-naltrexol is a minor metabolite in the monkey and guinea pig only, and (d) metabolic reduction of naltrexone occurs in the 100,000 x g supernatant of guinea pig liver. Pharmacokinetic studies of naltrexone in the dog and monkey indicate that the drug is rapidly distributed and eliminated, has a very large apparent volume of distribution and a total body clearance greater than the rate of liver blood flow.

Animals↗

PubMed1975

Testing of drug delivery systems for use in the treatment of narcotic addiction.

The evaluation of the drug release characteristic of four naltrexone delivery systems has been carried out together with the development of analytical techniques and an investigation of the metabolic profile of naltrexone. Pharmacologic evaluation of the four delivery systems in the mouse indicated significant analgesic antagonism for a period of from 16-22 days. Further evaluation of one of these systems by measurement of the rate of excretion of radioactivity after administration of radiolabelled naltrexone in the delivery system confirmed that significant release occurs for a time period of about 15 days. Electron capture gas-liquid chromatographic assays for naltrexone and naloxone in plasma or urine have been developed that yield linear calibration curves and are sensitive to one ng/ml. Studies on naltrexone disposition indicate that (a) binding to plasma proteins in several species varies from 20-26 per cent, (b) distribution of drug from blood is extremely rapid and extensive, (c) beta-naltrexol is a major metabolite of naltrexone in man, monkey and guinea pig among six species studied, whereas alpha-naltrexol is a minor metabolite in the monkey and guinea pig only, and (d) metabolic reduction of naltrexone occurs in the 100,000 x g supernatant of guinea pig liver. Pharmacokinetic studies of naltrexone in the dog and monkey indicate that the drug is rapidly distributed and eliminated, has a very large apparent volume of distribution and a total body clearance greater than the rate of liver blood flow.

Animals↗

PubMed1979

Safety of changing intravenous delivery systems at longer than 24-hour intervals.

Routinely changing the intravenous delivery system (fluid containers and administration set) every 24 h is widely practiced in American hospitals to reduce the risk of septicemia caused by contaminated infusate. We did a prospective clinical study to ascertain whether changing at longer intervals could be justified. At the conclusion of infusion therapy through one system, both the cannula and an aliquot of remaining fluid were cultured quantitatively. Of 790 infusions, contaminated infusate was detected in one (0.39%) of 258 discontinued and sampled after 1 to 24 h of continuous use, three (0.84%) of 259 after 25 to 48 h, and one (0.58%) of 173 after 49 to 71 h; none of these five contaminated systems produced septicemia. However, five cannula-related septicemias were identified during the study, none associated with concordant contamination of infusate. Routinely replacing the delivery system every 48 h seems to be justified and could result in considerable savings to hospitals. Infection of the cannula wound and contamination of infusate seem to be unrelated.

Bacteria↗

PubMed1978

Preparation and evaluation of a sustained morphine delivery system in rats.

A new drug delivery system to induce physical dependence to morphine in rats is described. The device consists of a silicone polymer containing a water soluble "carrier" material, sodium alginate, which swells on contact with moisture to release the drug. The silicone or silastic pellets formulated to contain morphine sulfate are very easily prepared and the advantages over existing methods to induce physical dependence to morphine are discussed. In addition, a comparison of the percent of drug released and withdrawal intensities in rats was made with a silastic-morphine sulfate pellet, silastic-morphine base pellet and a microcrystalline cellulose-morphine base pellet.

Animals↗

PubMed2026

Turnip Mosaic Virus-Based gRNA Delivery System for Plant Genome Editing.

Plant virus-based gRNA delivery systems offer a rapid alternative to stable transformation for CRISPR-mediated genome editing, but potyvirus-based platforms in Cas9-expressing plants are still underexplored. Here, we developed a turnip mosaic virus (TuMV)-based system for gRNA delivery in Cas9-expressing Nicotiana benthamiana and tested whether Csy4-mediated gRNA processing could improve editing efficiency. A TuMV construct carrying a gRNA targeting PHYTOENE DESATURASE (NbPDS) induced detectable editing in both infiltrated and systemic tissues, although editing frequencies were low. Incorporation of the bacterial endoribonuclease Csy4 increased editing efficiencies in the two NbPDS genes, raising editing in infiltrated leaves to 7.1%-13.8% for NbPDSa and 7.6%-23.0% for NbPDSb, whereas lower but reproducible editing was detectable in systemic leaves. The TuMV-Csy4 platform also supported editing of a second endogenous target, MAGNESIUM CHELATASE SUBUNIT H (NbChlH), and enabled multiplex editing of NbPDS and NbChlH regardless of guide order. Editing efficiencies were consistently higher in infiltrated leaves than in systemic leaves, and no visible photobleaching or chlorosis was observed in systemic tissues despite confirmed molecular editing. To assess the potential for heritable editing, a tRNAIle mobility element was fused to the NbPDS gRNA. Although this construct increased somatic editing, no albino progeny were recovered after screening approximately 20,000 seedlings, demonstrating that heritable editing was not achieved under these conditions or did not result in mutations in all copies of the two NbPDS genes. Together, these results establish TuMV as a platform for Cas9-based gRNA delivery and show that Csy4-mediated processing improves editing efficiency, supports multiplex targeting, and demonstrates the feasibility of potyvirus-based genome editing systems in plants.

genome editing platform↗

PubMedDate not supplied

An analysis of the processing of patients in a rural medical care delivery system.

A study of the processing of patients at the rural clinic of a medical care delivery system was done to describe quantitatively the movement of patients from their arrival to their departure. The data collected provided a statistical summary of the sequence and duration of observed events in the medical care process as they related to the patients. An analysis of 485 patients visits that were observed on 60 random days during a 12-month period showed that patient arrival rates were generally higher during the morning. The average visit lasted 74 minutes; 94 percent of this time was spent in the waiting and examination rooms. The period that that the patient spent unattended by clinic personnel represented three-fourths of the average patient's total time in the delivery system. Data analysis indicated that if patients were admitted to an unoccupied examination room as soon as possible after their arrival and if standing orders for the family nurse practitioner were expanded, a significant reduction would occur in the average patient's unattended visit time.

Appointments and Schedules↗

PubMed1976

Evaluation of an ambulatory medical-care delivery system.

We designed a medical-care-delivery system specifically to relieve the impaired access to care that has invariably assompanied the elimination of personal fees by prepaid plans, Medicare and other third-party payment plans. The solution involved the entry of patients through a paramedically staffed health-evaluation servece that effectively separated patients into three basic health-status groups-the well and worried well (68.4 per cent); the asymptomatic sick (3.9 per cent); and the sick (27.7 per cent)--a process that permitted matching the needs of each group with appropriate services. The system achieved increased physician accessibility to new patients by 20 times, reduced the waiting time for new appointments from six to eight weeks to a day or two, saved physician time and costs for entry work to a day or two, saved physician time and costs for entry work-up by 70 to 80 per cent reduced total resources used throughout the year by +32,550 per 1000 entrants, and proved very satisfactory to patients and generally so to staff.

Ambulatory Care↗

PubMed2026

Establishment of a cBSA-mediated miRNA delivery system in Camellia sinensis and functional validation of the Cs-miR163/CsSK1 module in cold stress response.

Cold stress severely limits tea (Camellia sinensis) yield and quality. MicroRNAs (miRNAs) are key post-transcriptional regulators of plant cold responses; however, in vivo functional validation in tea plants is hindered by the lack of efficient genetic transformation and nucleic acid delivery systems. In this study, a cationized bovine serum albumin (cBSA)-mediated miRNA delivery system was established in tea plants. The cold-responsive miRNA Cs-miR163 and its target gene CsSK1 (a negative regulator of cold tolerance) were used as a model. Direct cleavage of CsSK1 mRNA by Cs-miR163 was confirmed by 5' RLM-RACE and GUS transient expression assays, and enhanced cold tolerance was demonstrated in Arabidopsis overexpression lines. The cBSA preparation protocol was optimized, yielding stable cBSA/miRNA complexes with high protective capacity across temperatures of 15-35 °C and pH 4.5-7.2. Delivery parameters were systematically evaluated; optimal conditions were determined as 2 mg/mL cBSA with 10 nM miRNA and solution uptake into 3-cm cuttings for 5 days, enhancing miRNA delivery efficiency by approximately 48-fold. Transmission electron microscopy provided direct ultrastructural evidence that cBSA/miRNA nanocomplexes are internalized into tea plant cells via adsorptive-mediated endocytosis involving electrostatic membrane adsorption, membrane invagination, and cytoplasmic release. Under optimized conditions, cBSA-mediated delivery of Cs-miR163 silenced CsSK1 expression by approximately 72%, reduced relative electrolyte leakage and ROS accumulation, and markedly enhanced cold tolerance. The regulatory role of the Cs-miR163/CsSK1 module was clarified, and the established system provides a promising strategy for functional genomics in woody plants that warrants further testing in additional species and tissues.

Camellia sinensis↗

PubMed1975

The hazards of bulk oxygen delivery systems.

Many hospitals throughout the world obtain oxygen from a supply of bulk liquid oxygen which is delivered throughout the hospital via pipelines. An incident in which, through a series of malfunctions, dangerously high pressure developed in the hospital oxygen pipeline is described. The oxygen delivery systen described lacked a relief valve to vent excessive pressures. In North America such a relief valve is required on all oxygen delivery systems. An alarm system is also required which detects rises in pipeline pressures. Regulations in the U.K. do not provide for pressure-relief valves on liquid oxygen pipeline systems. In the U.K. there is also no regulation on alarms to warn of high pipeline pressures. High-pressure accidents are a real threat to patients and hospital staff unless proper safeguards are built into oxygen delivery systems.

Accident Prevention↗