TPE in infusion therapy

Dear Customer,

Complex application techniques and a wide variety of different and specific application systems are used for infusing medication and nutritional components as well as for the transfusion of blood and blood components in order to administer therapeutic substances to patients both correctly and successfully.

Compatibility and safety

After all, the goal is for the corresponding medication and nutritional components and/or blood products to find a correct and efficient way into the patient in order to achieve an optimal clinical result. Certified ACTEGA DS compounds used in medical technology and pharmaceuticals offer high potential benefits in infusion therapy.

During the compounding process, compatibility with medication, nutritional elements and blood products as well as patient and user safety are strictly observed. Highly-transparent PROVAMED® TPE, specially compounded for the manufacture of drip chambers, are distinguished by a well-balanced compressive force profile, optimized adhesion, and outstanding solvent bondability.

Currently, there are four basic formulae available with varying property profiles in terms of mechanics and fluidity, on the basis of which other individual developments and application-oriented recipe modifications are possible.

Origin and development of infusion therapy

Initial evidence of a blood transfusion dates back to 1492 when Pope Innocent VII suffered a stroke and was given blood by his physician from three young men by connecting their veins. But the process did not work as both the pope and the three young men died. This led to an initial ban and the concept of IV transfusion was not broached again for hundreds of years.

The German natural scientist Andreas Libavious touched on the topic in his book titled Alchemia (1597) and described an imaginative version of a blood infusion. It is not known whether he ever actually performed it.
In the early and mid-1600s, many different scientists, including Robert Hooke, Robert Boyle and Christopher Wren, conducted tests with opium infusions on dogs. Wren and his colleague Richard Lower used a quill and pig’s blood for the first blood transfusion on dogs (1665). After several attempts at animal-to-human transfusions – many of which went wrong – blood transfusions were banned for the second time. Once again, this topic disappeared into oblivion for years. It was not until 1795 when the American doctor Philip Syng Physick substantiated human-to-human transfusion. But an outbreak of cholera (1831/32) represented a breakthrough when it was acknowledged that the blood of dehydrated people needed to be treated with lukewarm water and salt. The precursors to IV sets, as they are now known, evolved from 1845 with the development of syringes and needles.

Design of an infusion set

Infusion systems or sets today comprise a mandrel for inserting into the plug at the infusion holder, a drip chamber with ventilation, a transparent infusion line, a flow regulator for controlling speed and through which the infusion fluid enters the body, and a connector for linking to the access point, e.g. a peripheral vein catheter. The drip chamber ensures regulated dripping of the liquid administered by infusion. While they were typically manufactured from PVC for years, there is now an increasing tendency to rely on alternative materials.

Top in terms of bonding ability and adhesion

Accordingly, TPE are a good choice. PROVAMED® TPE are distinguished by a well-balanced flexibility and rigidity as well as being highly transparent – for perfect optical control of the drip process along with swift and easy adjustment of the fluid level. They can be sterilized without impairing material properties or the function of bonding materials between the drip chamber and tube, and display an outstanding degree of solvent bondability with popular solvents such as tetrahydrofuran (THF), methyl ethyl ketone (MEK), and even with cyclohexanone and other solvents. Furthermore, perfect adhesion is offered, particularly to polystyrene, ABS or PVC.

Four components, various colors, one cycle

Multi-component technology is also the method of choice when it comes to the production of a particular mass consumer item – this product is sold worldwide more than six billion times a year: the toothbrush. Most manual toothbrushes today are manufactured from at least two to four plastic components and in various colors. 

Apart from typically thermoplastic materials for the basic body, design and haptics dictate that one or more flexible plastics such as thermoplastic elastomers are processed when overmolding the handle. This is the most efficient way to manufacture a three-component toothbrush using multi-component technology, for example.
The thermoplastic basic bodies which are identical for all toothbrushes of the same type are simultaneously overmolded with various handle colors in a multi-cavity injection-molding tool. Furthermore, another color or material can be processed during the same manufacturing cycle in order to apply an additional handle component such as a tongue cleaner to the back of the toothbrush head. One essential advantage over sequential production with various overmolding colors is that colors do not need to be changed during the production process. There is also a logistical advantage: if all colors are simultaneously injected in a tool, the 4-colored toothbrushes are directed to the packaging plant right from the conveyor belt. All in all, this saves material, time and storage costs.

However, multi-component technology also poses major challenges for the material. The substrate and overmolding can effectively complement each other. For this, the materials must be compatible. The materials to be selected depend on the function of the injection-molding parts and the respective manufacturing method. As the connection between the process and end product in multi-component injection molding is more complicated than for single-component injection molding, we recommend seeking expert advice when it comes to selecting materials. It is not, for example, only about the compatibility of plastics but also the particular requirements on adhesion. The material developments entail modifications of plastics enabling them to be optimized for the requirements of the actual products to be manufactured. For this reason, ACTEGA DS has adapted the TPE formulae to the special demands on optics, haptics, slip-resistance, secure grip and ergonomics. These SOFT EST. TPE are distinguished by their particular softness, easy coloration properties, good haptics, shorter cycle times in the injection-molding process, particularly good adhesion to PP and PE, and of course compliance with FDA und EU regulations. It is also possible to adapt these good adhesion properties to technical thermoplastics.

Find out for yourself about these and other applications at the ACTEGA DS stand at the K-Fair in Düsseldorf, October 16-23, 2019 in Hall 8A, Stand F 11-3.