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At least 19 recordsLinked to original sources

PubMed2000

Topical corticosteroid in foam vehicle offers comparable coverage compared with traditional vehicles.

BACKGROUND: A new preparation of betamethasone valerate in a novel foam vehicle is available for treatment of scalp dermatoses. The vehicle spreads between hair until it reaches the scalp, where it melts and delivers the active drug. Solids make up only a tiny fraction of the foam vehicle, leaving no apparent residue on the skin or hair. The uniqueness of this vehicle raises the question of how to compare it with other topical corticosteroid preparations. OBJECTIVE: The purpose of this study was to determine the equivalency of a given quantity of the foam product to quantities of drugs in conventional vehicles. METHODS: The number of fingertip units (FTUs) per gram and the area of coverage of an FTU of betamethasone valerate foam vehicle were determined and compared with those of cream, lotion, gel, and solution psoriasis treatments. RESULTS: The weight of an FTU of foam vehicle was 52.5 +/- 5.7 microg. There were 9 to 12 times as many FTUs in 100 g of vehicle foam as in 100 g of cream or gel and 2.3 to 2.8 times as many as in 100 g of lotion or solution. The area covered by an FTU of foam vehicle was less than the area covered by an FTU of cream or gel. CONCLUSION: The characteristics of foam vehicle are different from those of other vehicles. The greater number of FTUs in 100 g of foam vehicle made up for the lower coverage per FTU, such that total coverage area for 100 g of foam vehicle was comparable to the coverage area for 100 g of the drugs in traditional vehicles.

Administration, Topical↗

PubMed1987

Effect of skin pretreatment with vehicle alone or drug in vehicle on flux of a subsequently applied drug: results of hairless mouse skin and diffusion cell studies.

Clinical and in vitro evidence suggest that pretreatment of skin with a drug or vehicle can influence topical drug delivery. In this study, hairless mouse skin in diffusion cells was treated for 48 h with topical applications of vehicle alone (oleic acid (OA), isopropyl myristate, octanol (OCT), dimethylformamide, propylene glycol (PG), ethylene glycol (EG), formamide), or mixtures of OA and PG, or with 5-fluorouracil (5-FU) suspensions in each of these vehicles. Twenty-four hours after removing the initially applied agent, a standard suspension of theophylline in PG was applied to the skin surface and the flux of theophylline was determined over the next 48 h. Skin pretreatment with vehicle alone increased theophylline flux 1.6-(EG) to 122-fold (OCT) over control experiments in which the skins were not pretreated. Pretreatment with nonpolar vehicles with lower solubility parameters (OA, OCT, or mixed vehicles containing one of these) had the greatest effect on subsequent theophylline flux. Pretreatment with 5-FU in various vehicles caused a subsequent increased theophylline flux similar to the effect of vehicle alone, except for pretreatment with 5-FU in vehicles which did not have much effect themselves. In those instances, theophylline fluxes up to 16-fold over the effect of those vehicles alone were observed.

Animals↗

PubMed2002

Patients with psoriasis prefer solution and foam vehicles: a quantitative assessment of vehicle preference.

Psoriasis patients' acceptance of the vehicles used in topical therapy contributes to adherence to treatment plans and outcomes, but patient preferences for different vehicles have not been assessed. The purpose of this study was to develop a quantitative measure of patient preferences for different vehicles and to assess these preferences. Focus group sessions were conducted of patients with psoriasis to determine patient perceptions of the advantages and disadvantages of different topical psoriasis therapies. This information was used to derive a vehicle preference measure to assess different topical therapies. Twenty patients with psoriasis sampled different topical psoriasis medications, assessed the effects of the vehicles on quality of life (QOL), and completed the preference measure for each vehicle. The focus group sessions resulted in the development of a 7-item preference measure. The validity of the vehicle preference measure was demonstrated by good correlation with patient expectations of effects on QOL and by test-retest reliability. The foam and solution vehicles were preferred over the cream, gel, and ointment vehicles (P < .01). There was no significant difference between preferences for daytime and nighttime application of vehicles. Although validated measures of adherence to topical therapy are not yet available, the results of this study suggest that the characteristics of solution and foam may favor improved adherence to topical therapy.

Administration, Topical↗

PubMed2002

Vehicle weight and fatality risk for sport utility vehicle-versus-passenger car crashes.

BACKGROUND: This study examines whether mortality is greater in sport utility vehicles (SUVs) or passenger cars when these vehicles collide in a head-on crash. METHODS: This study analyzed the effect of vehicle weight in head-on crashes between passenger cars and SUVs between 1994 and 1999. Variables such as location of impact, safety belt use, vehicle weight, vehicle type, number of occupants, and number of fatalities were extracted from the Fatality Analysis Reporting System. RESULTS: Belted occupants of passenger cars involved in a fatal head-on collision with an SUV had a higher fatality rate (total deaths per vehicle type/total occupants per vehicle type) than belted occupants of the SUV (56.3% of passenger car occupants vs. 17.6% of SUV occupants). The difference in fatality rates is reduced when the weight of the passenger car is equivalent to the weight of the SUV but is still significant (45.6% of passenger car occupants vs. 26.5% of SUV occupants). In the 57 crashes where the passenger cars outweighed the SUVs by an average of 234 lb, the occupants of the cars still had a higher fatality rate than occupants of the SUVs (40.1% of passenger car occupants vs. 24.4% of SUV occupants). CONCLUSION: Occupants of passenger cars have a higher risk of fatality than occupants of SUVs in car-versus-SUV head-on crashes. Vehicle differential weight plays an important role in determining the safety of occupants involved in these crashes, but safety cannot be evaluated on the basis of vehicle weight alone. Other factors such as mismatches in vehicle design and structural load path must also be considered.

Accidents, Traffic↗

PubMed1992

Application of molecular encapsulation for toxicology studies: comparative toxicity of p-Chloro-alpha, alpha, alpha-trifluorotoluene in alpha-cyclodextrin vehicle versus corn oil vehicle in male and female Fischer 344 rats and B6C3F1 mice.

The application of alpha-cyclodextrin (alpha-CD) as an alternative vehicle for water insoluble and volatile chemicals was investigated in toxicity studies of p-chloro-alpha, alpha, alpha-trifluorotoluene (CTFT). Groups of F344 rats and B6C3F1 mice of each sex were administered CTFT (97% pure) by gavage in either corn oil or alpha-CD aqueous formulations daily for 14 consecutive days. The dose levels used were 10 (mice only), 50, 400, and 1000 mg/kg for corn oil vehicle and 10, 50, and 400 mg/kg (maximum achievable dose at gavage volume of 5 ml/kg) for alpha-CD vehicle. With both vehicles CTFT and alpha 2u-globulin were found to accumulate in the male rat kidney after 14 days of exposure and a dose-related toxic nephropathy was observed at dose of 50 mg/kg or higher. The hepatocellular hypertrophy and cytoplasmic vacuolation of the adrenal cortex which appeared in dosed male and female rats were also found to be independent of vehicle. Clinical pathology findings suggested a mild anemia and cholestasis in rats. With both vehicles no tissue bioaccumulation of CTFT was found in male or female mice. Vehicle-independent hepatocellular hypertrophy and cholestasis were also observed in mice at doses of 400 and 1000 mg/kg. In conclusion, the alpha-CD vehicle does not affect the toxic responses of CTFT in both sexes of both species. The results of the studies suggest that alpha-CD may be an appropriate alternative vehicle for toxicity studies.

Alpha-Globulins↗

PubMed1981

Effect of various vehicles and vehicle volumes on oral absorption of triamterene in rats.

The oral bioavailability of triamterene in rats was investigated after its administration as a suspension in lipid and aqueous vehicles in addition to lactic acid solution. Triamterene is poorly soluble in both aqueous and lipid vehicles. A 1-ml oral dose volume showed that lipid vehicles may provide some enhancement of oral availability compared with aqueous suspensions. However, when the vehicle volume was reduced to a realistic dosage form volume for the rat, peanut oil and aqueous suspensions were indistinguishable from each other with respect to peak height, peak time, and overall bioavailability. For a given vehicle small vehicle volumes resulted in a better relative oral availability than did large vehicle volumes.

Animals↗

PubMed1997

Two-vehicle side impact crashes: the relationship of vehicle and crash characteristics to injury severity.

Injury type and severity among front outboard occupants of passenger vehicles struck in the side by another passenger vehicle and recorded in the United States National Accident Sampling System Crashworthiness Data System were examined in relation to the location of impact, the angle of impact, occupant gender and age, seat belt use, the weight and body style of the side-impacted vehicle, and the weight and body style of the striking vehicle. Elderly occupants were three times as likely as younger occupants in similar crashes to be seriously injured. Serious injuries were also more likely for occupants seated on the struck side and occupants of lightweight passenger vehicles. After accounting for vehicle weight differences, struck-side occupants of cars were still much more likely to be seriously injured than struck-side occupants of light trucks. However, among occupants seated on the side of the vehicle opposite the impact, the likelihood of serious injury was higher for those seated in light trucks.

Accidents, Traffic↗

PubMed2003

Comparative analysis of vehicle-bicyclist and vehicle-pedestrian accidents in Japan.

Bicyclist and pedestrian injuries in collisions with vehicles in Japan were investigated based on national and in-depth accident data analyses and mathematical simulations. In an impact with a bonnet-type vehicle, a bicyclist slides over the bonnet of the vehicle, behavior that is not observed for pedestrians. As a result, the bicyclist's head tends to strike a bonnet-type vehicle at a more rearward location in comparison with pedestrians. The first contact position of a bicycle with a vehicle, the vehicle front-end geometry and the bicycle velocity affect whether the bicyclist's head strikes the vehicle or not. Due to the bent-knee posture of a bicyclist's legs, the types of leg injuries sustained by bicyclists and their causes differ from those seen for pedestrians. Component test procedures have been proposed for evaluating pedestrian safety, but some modifications of the head impact area and angle are necessary when applying these methods to bicyclists.

Accidents, Traffic↗

PubMed1999

Utilizing vehicle imbibition by a microporous membrane and vehicle viscosity to control release rate of salbutamol.

The possibility to control the release rate of salbutamol through the hydrophobic Celgard 2500 polypropylene membrane by varying the composition and the viscosity of hydrophilic drug vehicles was investigated. The use of the polypropylene membrane as a control membrane for reservoir-type drug delivery systems was envisaged and water, glycerol, isopropyl alcohol and ethanol, pure or as binary mixtures were studied as vehicles. With varying composition of the vehicle, a sharp change of its imbibition by the membrane from practically none to a complete filling of the membrane pores occurred, which coincided with a steep rise of the drug permeability for the membrane. From this was inferred that the vehicle-filled pores were the dominant permeation pathway, while when no vehicle was imbibed, transport took place by way of the polymer domain of the membrane. In case of imbibition, the permeation rate could be modulated in a predictable fashion by adjusting the viscosity of the vehicle. This demonstrated that drug release could be controlled by utilizing the in situ interaction of the vehicles with this membrane, leading to imbibition and establishment of a permeation pathway with pre-determined viscosity in the pores of the membrane.

Albuterol↗

PubMed1998

Development of emulsion type new vehicle for soft gelatin capsule. I. Selection of surfactants for development of new vehicle and its physicochemical properties.

Screening of surfactants was carried out to develop an oil in water (o/w) emulsion type new vehicle for a soft gelatin capsule (SGC), using polyethyleneglycol 400 (PEG 400) as hydrophilic phase and medium chain triglyceride (Miglyol 810), propyleneglycol dicaprylate (Sefsol 228) or soybean oil as hydrophobic phase (PEG 400: hydrophobic phase: surfactant = 87:10:3) and by means of simple homogenization. Polyoxyethylene (20) cetylether (BC-20TX), which can form homogeneous and viscous white gels using the above hydrophilic and hydrophobic phase combination, was selected as a model surfactant for developing the new vehicle. Using Miglyol 810 as hydrophobic phase, a model new vehicle formulation (PEG 400:water:Miglyol 810: BC-20TX = 77:10:10:3) was prepared, and its physicochemical properties were evaluated. The particle size distribution of the new vehicle, after diluting about 3000 times with water, ranged from about 0.5 to 50 microns. Furthermore, the new vehicle had thixotropic property at room temperature (about 25 degrees C) and temperature-dependent gel-sol transforming property with the transformation temperature of about 37 degrees C. These properties meet the requirement for encapsulation of the new vehicle in SGC and suggest that it can be expected to form the o/w emulsion state in the aqueous environment in the stomach. The rheological properties would also make it advantageous for use in other dosage forms such as suppository, cataplasm or liniment.

Capsules↗

PubMed1999

Emulsion type new vehicle for soft gelatin capsule available for preclinical and clinical trials: effects of PEG 6000 and PVP K30 on physicochemical stability of new vehicle.

To prevent temperature-dependent gel-sol transformation of an o/w emulsion type new vehicle system for a soft gelatin capsule, which may be available for both preclinical and clinical trials, the basic new vehicle formulation (PEG 400:purified water:medium chain triglyceride:polyoxyethylene (20) cetylether = 77:10:10:3) was modified by partially (1, 2 or 3%) replacing PEG 400 with PEG 6000 or PVP K30. When 2 or 3% of PEG 400 was replaced with PEG 6000, temperature-dependent gel-sol transformation was prevented at temperatures below 40 degrees C, and the vehicle appeared to be stable during 8 weeks of storage at 4 to 40 degrees C; the particle size distribution remained unchanged. When 1% of PEG 400 was replaced with PEG 6000, gel-sol transformation was not prevented, though phase separation was not observed at sol state, and the particle size distribution was shifted to be in a larger particle size range after 2 weeks of storage. When PEG 400 was partially (1, 2 or 3%) replaced with PVP K30, temperature-dependent gel-sol transformation was not prevented and, after 2 weeks of storage at 40 degrees C, the particle size distributions of the vehicles were shifted to be in a larger particle size range and the vehicles were separated into two layers. These results suggested that a small amount of PEG 6000 plays an important role in preventing temperature-dependent gel-sol transformation of our developed vehicle system.

Capsules↗

PubMed1998

Car occupant safety in frontal crashes: a parameter study of vehicle mass, impact speed, and inherent vehicle protection.

A new mathematical model was developed to estimate average injury and fatality rates in frontal car-to-car crashes for changes in vehicle fleet mass, impact speed distribution, and inherent vehicle protection. The estimates were calculated from injury fatality risk data, delta-V distribution and collision probability of two vehicles, where delta V-depends on impact speed and mass of the colliding vehicles. The impact speed distribution was assumed to be unaffected by a change in fleet mass distribution. The results showed that safety in frontal crashes would improve 27-35% by a 10% increase in fatality risk parameters, which reflected substantial improvement in inherent vehicle protection. A 40% safety improvement was attained by a 10% impact speed reduction. Consequences of vehicle fleet mass were not as strong, but depended on the average mass ratio of the fleet. A reduction in mass range would be the most beneficial, while a uniform mass reduction of 20% would increase the fatality rate by 5.4%. The model estimates trends in traffic safety and may help to identify priorities in active and passive safety.

Acceleration↗

PubMed1990

[An experimental study on driver identification of passenger car in vehicle to vehicle accidents].

A series of full-scale vehicle-to-vehicle oblique collision experiments was carried out for providing general data to clarify the question of seating positions. In all test, two unrestrained anthropometric dummies (Hybrid II) were seated on front seats in passenger cars as occupants. The bullet car collided against the target car running with 25 km/h, at 50 km/h, at impact angles of 120 degrees and 150 degrees. Five impact configurations between occupant regions and interior of vehicle were evaluated: head-face/windshield, head-face/A-pillar, chest-abdomen/instrument panel, upper body/inside door and lower extremities/instruments panel. Comparative occupant injuries and vehicle response data were obtained from electronic instrumentation, high-speed movie films and visual observations. No characteristic driver injuries was observed in oblique collision experiments. The crush characteristics of the vehicle interiors and occupant behavior had significant effect in determining the actual injury once contact occurred. The differences of injuries in occupants occurred depend on impact configurations of vehicles. Therefore, on the driver identification, it is important to clarify kinematics of occupants during the impact by an analytical reconstruction. The data and information can be used to determine who was driving in actual traffic accidents for the forensic medicine expert.

Accidents, Traffic↗

PubMed1985

Noncrash motor vehicle accidents. Injuries to children in the vehicle interior.

Injuries caused by hitting against the vehicle interior during a noncrash motor vehicle accident are noteworthy. Data on children 0 to 15 years of age involved in motor vehicle accidents were obtained from an ongoing multihospital monitoring system. Approximately 12% of the passengers were injured in a noncrash accident. One half of the noncrash injuries were caused by a child hitting against the vehicle interior during a sudden stop, turn, or swerve or after losing balance in a moving vehicle. Most of these accidents involved a child between 1 and 4 years of age who was traveling in the front passenger seat unrestrained. While most of the injuries were minor, some children sustained serious injuries. An analysis of the cases indicated that most of these injuries could have been avoided if the child had been restrained. Medical costs as well as use of medical resources could have been saved by preventing these noncrash injuries.

Accidents, Traffic↗

PubMed2002

[Bicycle accidents. Differences between one-vehicle accidents and accidents involving two or more vehicles].

INTRODUCTION: Bicycle accidents are the most frequent traffic accidents in Denmark. Most of these accidents are one-vehicle accidents. The aim of this study was to investigate the differences between one-vehicle accidents and accidents with a counterpart in order to suggest focused prevention. MATERIALS AND METHODS: The analysis was based on data of the Danish Accident Registry using all bicycle accidents reported to five Danish emergency departments in the period 1998-2000. RESULTS: 81% of the bicycle accidents were one-vehicle accidents which frequently resulted in injuries of the upper extremities. They frequently resulted in fractures and open wounds compared to other bicycle accidents. For intoxicated bicyclists, 95% were one-vehicle accidents, and injuries to the head constituted 63% of the injuries. DISCUSSION: One-vehicle accidents often result in severe injuries indicating a need for prevention. Special attention should be given to the young and the elderly. Although many bicycle accidents have no immediate cause, preventive measures should be taken, such as better clearing of roads and bicycle tracks and campaigns against drink-riding.

Accidents, Traffic↗

PubMed2001

Real-world vehicle emissions: a summary of the tenth coordinating research council on-road vehicle emissions workshop.

The Coordinating Research Council (CRC) held its tenth workshop in March 2000, focusing on results from the most recent real-world vehicle emissions research. In this paper, we summarize the presentations from researchers who are engaged in improving our understanding of the contribution of mobile sources to emission inventories. Participants in the workshop discussed efforts to improve mobile source emission models and emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles, new methods for measuring mobile source emissions, improvements in vehicle emission control systems (ECSs), and evaluation of motor vehicle inspection/maintenance (I/M) programs, as well as topics for future research.

Environmental Exposure↗

PubMed2002

The effects of the catalytic converter and fuel sulfur level on motor vehicle particulate matter emissions: gasoline vehicles.

Scanning mobility and electrical low-pressure impactor particle size measurements conducted during chassis dynamometer testing reveal that neither the catalytic converter nor the fuel sulfur content has a significant effect on gasoline vehicle tailpipe particulate matter (PM) emissions. For current technology, port fuel injection, gasoline engines, particle number emissions are < or = 2 times higher from vehicles equipped with blank monoliths as compared to active catalysts, insignificant in contrast to the 90+% removal of hydrocarbons. PM mass emission rates derived from the size distributions are equal within the experimental uncertainty of 50-100%. Gravimetric measurements exhibit a 3-10-fold PM mass increase when the active catalyst is omitted, which is attributed to gaseous hydrocarbons adsorbing onto the filter medium. Both particle number and gravimetric measurements show that gasoline vehicle tailpipe PM emissions are independent (within 2 mg/mi) of fuel sulfur content over the 30-990 ppm concentration range. Nuclei mode sulfate aerosol is not observed in either test cell measurements or during wind tunnel testing. For three-way catalyst equipped vehicles, the principal sulfur emission is SO2; however a sulfur balance is not obtained over the drive cycle. Instead, sulfur is stored on the catalyst during moderate driving and then partially removed during high speed/load operation.

Air Pollutants↗

PubMed2000

Real-world vehicle emissions: a summary of the Ninth Coordinating Research Council On-Road Vehicle Emissions Workshop.

In April 1999, the Coordinating Research Council sponsored a workshop focusing on our understanding of real-world emissions from motor vehicles. This summary presents the latest information on in-use light- and heavy-duty vehicle tailpipe and evaporative emissions, the effects of fuels on emissions, field programs designed to understand the contribution of mobile sources to emission inventories, efforts to evaluate and improve mobile source emission models, progress of vehicle inspection/maintenance programs, and topics for future research. While significant progress has been made in understanding in-use vehicle emissions, further improvements are necessary. Moreover, the impact of current and future changes in emission control technologies and control programs will have to be monitored for effectiveness and incorporated into the emission factor models.

Air Pollutants↗