Mike Schaefers

Building on a long history of reconstitution, two companies devise a new system for sterile water for injection intended to promote ease of use and dosing.

The process of freeze-drying injectable drugs by removing water from the material and sealing the material in a vial, known as lyophilization, was developed in the mid-1930s. Since then, lyophilization has created a faster and more convenient path for many new drugs, including biologics, to reach the market. While certain drug products may be available as a liquid, many are not stable within an aqueous solution, and thus cannot be shipped or stored easily. Such products may require lyophilization for their entire life cycle.

There are several advantages to the lyophilization process. Lyophilization can help to extend the shelf-life of a drug product while maintaining drug potency. In addition, the drug product may withstand broader temperature ranges; it can also be shipped and stored easier than liquid counterparts that often require restrictive storage conditions. While these benefits have made lyophilized drug products an excellent option for many pharmaceutical manufacturers, lyophilized products require additional preparation prior to administration. To reconstitute a drug, the dry cake must be mixed with a liquid. The use of sterile water for injection creates an injectable solution that can be easily transferred to the patient.

Traditionally, two vials have been required to reconstitute a drug product. The first vial contains the lyophilized drug, while the second contains the diluent.

Since the diluent may not be measured precisely, the patient may be at risk of an under- or overdose. In addition, a disposable syringe and two needles are often used during the traditional reconstitution process. Given the risk of an accidental needlestick injury, experience and training are required to ensure that the process is completed correctly and the drug product administered safely.

To achieve a precise dose, the diluent used during the reconstitution process must be measured exactly. The use of a sterile, prefilled, water-for-injection syringe enhances the reconstitution process by enabling pharmaceutical companies to include a precise dose of diluent to accompany its drug product, thus making the product safer for the end-user. The prefilled syringe, when used in conjunction with a reconstitution system such as a vial adapter, removes at least one needle from the reconstitution process. This helps to reduce the changes for needlestick injuries and to enhance administration safety.

Although a small number of manufacturers currently provide water-for-injection services, the market has historically lacked a sterile prefilled water-for-injection syringe. To fill the need for a high-quality, sterile, water-for-injection prefilled syringe, component manufacturer West Pharmaceutical Services Inc. has joined forces with Vetter, an independent provider of aseptically prefilled syringes, cartridges, and vials. Together, West and Vetter have created a commercially available, high-quality sterile water-for-injection syringe. The syringe is aseptically manufactured with components that meet USP, Ph. Eur., and J.P. requirements.

After several years of development and testing, the water-for-injection syringe system is ready for commercial use. Produced at Vetter, the syringe includes a West plunger with FluroTec barrier film to enhance lubricity and reduce the risk of contamination. In addition, a V-OVS tamper-evident closure system with luer lock adapter and tip cap manufactured with West’s 4023/50 gray formulation help to provide security and safety for the end-user.

Uniquely, the sterile water-for-injection syringe allows a variety of fill volumes ranging from 0.5 mL to 3.0 mL. Customers can select either a 1.5 mL or 3 mL syringe, depending on the fill volume required for their product.

The sterile water-for-injection syringe filled with the precise quantity of diluent needed for proper administration allows pharmaceutical companies to offer a product that not only provides the benefits associated with lyophilization, but also can enhance end-user safety. When used in combination with reconstitution systems already on the market, pharmaceutical companies have the option to provide a total package solution that can differentiate their product in a crowded market.

This article was written by Mike Schaefers, West Pharmaceutical Services, and Thomas Otto, Vetter.