Hypodermic needle, development

In electrostatic atomization, an electrical potential is applied between a liquid to be atomized and an electrode placed in the spray at a certain distance from liquid discharge nozzle. As a result of the mutual repulsion of like charges accumulated on the liquid surface, the surface becomes unstable and disrupts when the pressure due to the electrostatic forces exceeds the surface tension forces of the liquid. Droplets will be generated continuously if the electrical potential is maintained above a critical value consistent with liquid flow rate. Both DC and AC systems have been employed to provide high electrical potentials for generating fine droplets. Many configurations of electrode have been developed, such as hypodermic needles, sintered bronze filters, and cones. 

Opioids are administered in several ways. Opium was most commonly taken recreationally by smoking, but intravenous administration has become most common since the isolation of opium alkaloids and invention of the hypodermic needle. The development of heroin from morphine at the turn of the twentieth century led to more intense euphoric effects and greater risk for addiction. Heroin may also be snorted, or it can be smoked when added to a medium such as tobacco. Medically, opioids are commonly given through oral, subcutaneous, intravenous, transdermal, or rectal routes. 

Meanwhile, opium had been joined by other narcotics. Back in 1805 a German pharmacist s assistant had discovered how to isolate its main ingredient, morphine. A preparation of morphine is about 10 times as potent as raw opium. In 1832, another morphine derivative called codeine was isolated. By the 1850s, a more effective way to administer these powerful narcotics was developed—the hypodermic needle. During the American Civil War, battlefield surgeons had one effective way to relieve the pain of a shattered limb or punctured lung—an injection of morphine. Soldiers who survived their wounds after this treatment often became addicted to the drug. Morphine addiction was thus sometimes referred to as the soldier s disease. ... 

A schematic diagram of the ESI interface for LC-MS, developed by the group of Feim [11-13], is shown in Figure 5.2. Sample solutions enter the spray chamber through a stainless-steel hypodermic needle at a flow-rate of 5-20 pl/min. The... 

Chambers for oxygen consumption measurements are prepared from microscopic slides coated with a thin paraffin film. With a tip of a hypodermic needle held in a micromanipulator, a small round dent of 10—15 pm is made in the paraffin film, and a drop of 40% HF applied to the dent enables the formation of small circular cavities visible after the removal of paraffin. To increase the measuring capacity, an automatic cuvettechanging device has been developed. The object stage maintained at constant temperature by water circulation from a temperature controlled bath, is moved in six discrete steps by a synchronous motor. Thus, oxygen consumption in six different chambers can be assayed simultaneously. The basic equipment used for microspectrophotometric determinations of oxygen consumption does not differ essentially from the equipment used for other purposes, such as cytophotometry (Hamberger et al., 1975). 

This was the first type of polymer used in pharmaceutical applications, and was found to have desirable characteristics in that its resilience provided sealing properties and this resilience could be developed to allow the rubber to be pierced by a hypodermic needle, resealing after removal. This high level of resilience is partially due to its chemical structure, it being a straight chain elastomer (Figure 12.1). 

An accelerator is a device in which an electric field is developed by application of a voltage at opposite ends of a linear path. The greater the voltage, the faster the speed of the electrons the faster the speed of the electrons, the greater their penetrative power through matter. For practical sterilization purposes, accelerators of less than 100 MeV are being used for products such as hypodermic needles in which the requirement for penetration is minimal. 

In the interim there are other important health care applications for silicone fluids. Many of these involve its use as a lubricant. The availability of silicone fluid as a lubricant for use on disposable hypodermic needles (Figure 24) contributed to the development of the disposable hypodermic needle. Essentially all disposable hypodermic needles are lubricated with silicone fluid to permit easy insertion and removal, and to minimize pain. Prior to the use of silicone fluid lubricants disposable needles tended to be very painful and sometimes broke or bent upon insertion. 

Peristalsis-free pump, PHD 2000 Advanced Syringe Pump (Harvard Apparatus). For the stimulation of development with cAMP pulses, 10-mL syringes are connected with a hypodermic needle to 0.75 x 1.22 mm polyethylene tubing (LABOKRON 46470). 

Further development of the pH probe for practical use was continued by Markle and colleagues [21]. They designed the fiber optic probe in the form of a 25-gauge (0.5 mm OD) hypodermic needle, with an ion-permeable side window, using 75-p.m-diameter plastic optical fibers. The sensor had a 90% response time of 30 s. With improved instrumentation and computerized signal processing and with a three-point calibration, the range was extended to 3 pH units, and a precision of 0.001 pH units was achieved. 

An entirely different method, using reduced pressure to generate an aerosol, has been developed by Sega and Lee (1970) for drosophila. It also works well on habrobracon. Habrobracon are placed into serum bottles, and the bottles are stoppered with rubber vacuum caps coated with vacuum grease. A vacuum of about 5% atmospheric pressure is applied to the bottle by piercing the cap with a hypodermic needle attached to vacuum tubing... 

Yang el al. developed Pitot-static tube probes to measure radial gas velocity profiles at different heights in their riser [68]. They encased 0.5 mm ID hypodermic needles in a 5 mm OD tube. The static tube was sealed at the tip, and two 0.5 mm holes were drilled perpendicular to the planes of the tube 10 mm from the tip. The tip of the impact tube was flush with the surface. Using a standard equation for Pitot static tubes gives the local velocity. 

Mataix et al. [44] adopted a similar approach intended to reduce the use of NAD+. It also exploited an online sample DU prior to enzymatic reaction developed inside two different minicolumns packed with immobilized LDH and MDH for lactic and malic acid determination, respectively. Better control of NAD consumption was achieved by inserting a syringe with a hypodermic needle into the loop of the injection valve to spare this reagent. Sample volume was defined by an injection valve inserted before the DU, as exemplified in the manifold shown in Figure 12.4c. For sequential determination of the organic acids, the dialysate was introduced into the analytical path coupled to an additional injection valve, which was operated to fill a loop of 80 0,L. The rest of the solution was transported to the MDH minicolumn for malic determination. After an established length of time, the additional valve was switched and the sample loop of 80 pL was... 

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