Potential remote drug delivery failures due to temperature-dependent viscosity and drug-loss of aqueous and emulsion-based fluids

2021 ◽  
Vol 13 (2) ◽  
pp. 17639-17645
Author(s):  
Derek Andrew Rosenfield ◽  
Alfred Acosta ◽  
Denise Trigilio Tavares ◽  
Cristiane Schilbach Pizzutto
Keyword(s):  
Drug Delivery ◽  
Storage Temperature ◽  
Second Phase ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Viscosity Change ◽  
Oil Emulsion ◽  
Drug Loss ◽  
Dependent Viscosity ◽  
Transfer Needle

The ability to inject wild animals from a distance using remote drug delivery systems (RDDS) is one of the most effective and humane practices in wildlife management.  Several factors affect the successful administration of drugs using RDDS.  For example, temperature-dependent viscosity change in aqueous (Newtonian) or water-in-oil emulsion (non-Newtonian) fluids, commonly used in tranquilizer and adjuvant-based vaccines, respectively, can potentially result in drug delivery failure.  To better understand impacts due to viscosity changes, we investigated the fluid dynamics and ballistics involved in remote drug delivery.  Our research was divided into two phases: we investigated the viscosimetric physics in the first phase to determine the fluid behavior under different temperature settings, simulating recommended storage temperature (7ºC), plus an ambient temperature (20ºC).  In the second phase of our study, we assessed the drug delivery efficiency by specialized darts, using a precision CO2 projector and a blowgun. Efficiency assessment was done by comparing the original drug volume with the actual volume injected after firing the dart into a fresh pork hide mounted on a ballistic gel.  Before testing, we configured the required minimum impact velocity for our parameters and intramuscular injection (determined as ˃ 40 m/sec).  All executed dart-deployments performed satisfactorily, despite initial concerns of potential incomplete drug delivery, however, noteworthy drug loss was observed (˃10%) associated with drug residues in syringe/dart dead space and within the transfer needle.  This could potentially result in inaccurate dosing depending on the drug used.  Furthermore, the use of a blowgun for remote drug delivery (>3m) is discouraged, especially when using specialized darts, as the required minimum dart velocity for adequate penetration is difficult to reach, in addition to a loss of precision during targeting. 

Elastic-plated gravity currents with a temperature-dependent viscosity

2016 ◽  
Vol 805 ◽  
pp. 88-117 ◽  
Author(s):  
Clement Thorey ◽  
Chloé Michaut
Keyword(s):  
Peclet Number ◽  
Gravity Currents ◽  
Spreading Rate ◽  
Phase Changes ◽  
Second Phase ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Péclet Number ◽  
Viscosity Contrast ◽  
Dependent Viscosity

We develop a set of equations to explore the behaviour of cooling elastic-plated gravity currents for constant influx conditions. In particular, we introduce a temperature-dependent viscosity to couple the flow thermal structure with the velocity field. We show that this coupling results in important deviations from the isoviscous case. In particular, the bending and gravity asymptotic regimes, characteristic of the isoviscous case, both split into three different thermal phases: a first ‘hot’ isoviscous phase, a second phase where the spreading rate drastically decreases and the flow thickens and a third ‘cold’ isoviscous phase. The viscosity that controls the spreading rate differs in both asymptotic regimes; it is the average viscosity of a small peeling region at the current tip in the bending regime and the average flow viscosity in the gravity regime. In both regimes, we characterize the evolution of the thermal anomaly and determine the time scale of the phase changes in terms of the Péclet number and of the viscosity contrast. Finally, we show that the evolution with bending and gravity can result in six different evolution scenarios depending on the combination of dimensionless numbers considered. We provide a phase diagram which summarizes them as a function of the flow Péclet number and viscosity contrast.

Thermocapillarity and Thermoviscosity Effects on the Spin Coating of Wetting Liquids Above an Axisymmetrically Heated Disk

2005 ◽  
Author(s):  
Lin Wu
Keyword(s):  
Spin Coating ◽  
Disk Center ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Radial Temperature ◽  
Viscosity Change ◽  
Heated Disk ◽  
Depletion Rate ◽  
Dependent Viscosity ◽  
Wetting Liquid

The spin coating of wetting liquid on an axisymmetrically and radially heated disk is studied numerically under lubrication and zero Biot number assumptions. Our results show that both thermocapillarity (temperature dependent surface tension) and thermoviscosity (temperature dependent viscosity) effects can be harnessed to enhance the depletion rate of the spin coated liquid film if the disk center is hot. When the applied radial temperature profile has a steep change, an anchored shock wave is generated with a strength determined by the temperature induced viscosity change.

scholarly journals Viscosity effect on the strategic kinetic overgrowth of molecular crystals in various morphologies: concave and octapod fullerene crystals

RSC Advances ◽  
2021 ◽  
Vol 11 (34) ◽  
pp. 20992-20996
Author(s):  
Kwangjin Song ◽  
Jin Young Koo ◽  
Hee Cheul Choi
Keyword(s):  
Molecular Crystals ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Viscosity Change ◽  
Organic Molecular Crystals ◽  
Viscosity Effect ◽  
Crystallization Solution ◽  
Dependent Viscosity

A kinetic overgrowth allowing organic molecular crystals in various morphologies is induced by temperature-dependent viscosity change of crystallization solution.

Sign in / Sign up

Export Citation Format

Share Document