Dispensing devices

Toothpastes are packaged in flexible tubes, other flexible containers, and mechanically operated pump dispensers. They are usually extmded as cylindrical ribbons of a cohesive, smooth paste, approximately 2.54 cm in length and weighing approximately 1.5 g. New or modified dispensing devices are continually introduced to increase consumer interest. 

Typically, tablets are fed to the bodies through a tube and are simply released in the required number as the body passes beneath. Pumpable liquid fills are dosed by conventional liquid-dispensing devices. 

THD requires careful observation of the stringers (elastic, thread-like attachments) formed when the agents are transferred or dispensed. These stringers must be broken cleanly before moving the contaminating device or dispensing device to another location, or unwanted contamination of a working surface will result. 

Fig. 2. Salt cup dispensing device Metal pin A connects rotating Teflon disc C to upper glass joint stationary Teflon disc D is anchored by pins at B...

The closure may also have to act as a dispensing device in some designs. 

Mamajek, R.C., and Moyer, E.S. 1980. Drug dispensing device for administering beneficial drug at programmed rate, US Patent 4,207,890, 17 June 1980. 

Theeuwes, F., and Higuchi, T. Osmotic dispensing device for releasing beneficial agent, ALZA Corporation, Palo Alto, CA, U.S. Patent 3,845,770, 1974. 

Murray M. 2001. Automated Medication Dispensing Devices. Available at www.ahcpr.gov/clinic/ptsafety/pdf/ chapll.pdf. 

Automated dispensing machines have become common on nursing units in many hospitals. The nurse must enter a security code and a password into the dispensing device, along with the name of the patient and the name of the medication, before the machine will allow access to remove the medication. This system allows better control of items kept on the nursing unit and serves as a check for the nurse who retrieves the... 

Automated dispensing devices create several situations that can easily result in errors. While these machines are routinely restocked, the wrong drug still can be placed into the wrong bin during this process. Devices that have multiple medications in each drawer and/or that do not require pharmacist review of orders before access have drawbacks that are identical to the flaws in traditional floor-stock systems ... 

Currently, liquids are most conveniently handled by pipette tips for aspiration and dispensing into microtitre plates. Recently, acoustic energy driven liquid dispensing devices have been available (e.g. the ECHO550 or EDC system), such that liquid can be transferred in small volume (nanolitre to pL) accurately and directly from the wells on one plate into wells on another plate. 

With the advent of computers and the introduction of automated dispensing devices, the idea of a perpetual inventory is within the grasp of today s pharmacy. Further, the routine use of barcoding allows integration of point-of-care inventory management systems. In such systems, the inventory is constantly inspected and ordering and restocking takes place much faster. 

Mamajek, R.C. Moyer, E.S. Drug-Dispensing Device and Method. US Patent 4207890, June 17, 1980. 

Twenty-one dispensing programs can be stored in memory and retrieved. This type of liquid dispensing device can also be obtained as a computer-controlled system. 

Strong acids, caustic materials, and strong oxidizing agents should be dispensed by a commercially available automatic dispensing device. Under no circumstances is mouth pipetting permitted. 

A standard solution (or a standard titrant) is a reagent of known concentration that is used to carry out a titrimetric analysis. A titration is performed by slowly adding a standard solution from a buret or other liquid-dispensing device to a solution of the analyte until the reaction between the two is judged complete. The volume or mass of reagent needed to complete the titration is determined from the difference between the initial and final readings. A volumetric titration process is depicted in Figure 13-1. 

Microplate EIA have also been automated. These systems consist in microplate carriers, dilution and dispenser devices for multiple samples, washers and shakers, photometer (through-the-plate reading) and a processor for multiple reading (desk-top calculator or microcomputer interfaced with the measuring equipment). Compared to other systems, EIA requires less sophisticated equipment for reliable results, available from various commercial sources. 

Interaction of administration sets and dispensing devices with parenteral drug products, where warranted, should also be considered through appropriate-use test protocols to assure that absorption and adsorption during dwell time do not occur. 

Testing for extractables and leachables on stability studies may be appropriate in situations where other qualification tests have not provided sufficient information or assurance concerning the levels of extractables and leachables from plastics and elastomeric components. Interaction of administration sets and dispensing devices with parenteral drug products, where warranted, should also be considered through appropriate use test protocols to ensure that absorption and adsorption during dwell time do not occur. 

As defined in European directive 94/1/EC, cans are made of metal, glass, or plastic and are intended to be used once only [6-117]. They can contain compressed, hquefied, or dissolved gases with or without liquid, paste, or powder, which are equipped with a dispensing device that enables the contents suspended in a gas to be released as foam, paste, or powder or in liquid form. 

T. Schiesser, E. Menard, T. Smith, and X Akin, Microdynamic solder pump drop on demand eutectic SnPb solder dispensing device. Proceedings, Surface Mount International, San Jose, CA, 1994, 501-509. 

One melting device and pump may serve several dispensing devices. For automatic applications, controls must be available that detect the presence of a substrate, and insure that the adhesive is deposited in the desired location. Both mechanical and optical sensors can be used for these purposes. 

Fitments are another set of devices associated with closures. These are components that are used In conjunction with a closure to provide some added utility by reguiating the flow of product out of the package. A common example is the shaker top on a spice jar. When the dispensing device is built into the closure, instead of in a separate piece, the result is sometimes referred to as a fitment closure. 

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