In recent years, diabetes has been on the rise year by year. The use of insulin has become more widespread as mankind's understanding of diabetes has gradually deepened, further defining the importance of insulin in the treatment of diabetes. Since insulin needs to be injected on a daily basis, thus, most of the injections for patients occur at home. Insulin pen injectors have been widely used for their accurate injection dose, simple operation, easy portability and suitability for home use.

1. The concept of pen injectors

The concept of pen injector was born in the late 20th century, named after its pen-shaped appearance, mainly used in insulin injection, also known as insulin pen or pen injector. A pen injector consists of a cap, a refill, a barrel and a needle. Insulin is stored in the pen cartridge, and before use, the injection needle is protected from accidental puncture by the pen cap. When in use, the pen cap is removed to expose the injection needle for drug delivery. Pen injectors can be divided into single-use pen injectors and multiple-use pen injectors according to whether the refill can be replaced; according to the different ways of energy transfer, it is divided into mechanical pen injectors and electric pen injectors. Different manufacturers use different structures of pen injectors due to different insulin used, and most of them are not compatible with each other.

Improvements to pen injectors are mainly centered on the cartridge and barrel parts. Improvements to the pen cartridge are mainly in the convenience of its replacement and the convenience of drug storage and release; improvements to the injector barrel part are mainly in the convenience of its operation by the patient. In addition, the incidental functions of the pen injector have been gradually added. For example, the addition of dosage setting and sound prompts after the completion of the injection, which is convenient for patients with visual impairment to use. All of these improvements are essentially aimed at making the operation easier for the patient and avoiding the adverse effects of misuse.

2. Key technologies for pen injectors

1. Needles

Needles are generally composed of a needle holder, a connecting part, a needle tube, a protective cap, a protective jacket and a sealing film, etc., and are made of stainless steel, polypropylene, polyethylene and other materials. Needles should in principle be used once, and cannot be sterilized by alcohol wiping or rinsing or soaking. Repeated use will not only increase the pain of injection, but also cause needle clogging, leakage, and contamination of the medicine over time. For the improvement of needles, it mainly lies in the improvement of processing technology to make its size become finer, reduce the pain of injection, and through the use of new materials, make its performance better.

2. Refills

A pen refill is a specially designed vial for storing insulin. Generally specific refills are used with specific insulin pens and are not compatible between different manufacturers. A refill has a body, a rubber piston, and a connecting part. The main body stores the insulin, the connecting part is used to connect to the needle, and the rubber piston is used to connect to the plunger of the injector barrel to enable pushing of the medication during injection.

3. Injection Barrel

The injection cylinder includes an injection push button, a dose setting part, a dose display window and a piston drive mechanism. The dose setting component realizes the setting and adjustment of the injection dose, and the dose display window is used to display the set dose. The piston drive mechanism is used to drive the piston in the cartridge to realize drug delivery. The piston drive mechanism is categorized into two types, electric drive and mechanical drive, due to the different ways of energy transfer. Mechanical actuators require manual adjustment of the dosage setting component to achieve the setting. Motorized actuators allow for automatic setting and injection through one-button operation.

3. Pen injector application range

According to statistics, in 2010, 285 million people worldwide suffered from type II diabetes, accounting for almost 90% of the total number of diabetes patients. Insulin injection has become a commonly used method in diabetes treatment due to its advantages of low side effects and remarkable effect. Pen syringes have become the preferred choice of type II diabetes patients due to their ease of use and rising demand for their use.

Since pen injectors have been introduced into China for a relatively short period of time, there are still a lot of problems in the use of pen injectors by patients. The main problems include: inaccurate selection of the injection site, incomplete sterilization, incorrect storage of the refill, insufficient venting before injection, and incorrect needle retention time and withdrawal techniques. It is necessary to conduct training related to the operation and preservation of pen syringes for diabetic patients, so as to make their use more standardized.

4. Conclusion

As a convenient and simple injection technique, pen injector will gain more and more attention and use by diabetic patients, which will promote the faster development of pen injector. With the development of technology, the R&D and manufacturing of pen injectors in China will also become more mature, which will bring more products to the market.

The information is from the Internet and is for reference only.