Lyophilization

When is lyophilization needed?

Lyophilization (freeze-drying) may be beneficial if the product is insufficiently stable or if the exact dosage is not possible using dry, aseptic filling. Lyophilization may also be advantageous if the substance is sensitive to heat, humidity or oxygen. In addition, a drug can also be lyophilized when the dose is very small and highly concentrated, or when precise dosing is absolutely imperative.

The lyophilization process

• Step 1 – Freezing: Product is frozen in its final container at low temperatures, for example - 60 C°.
• Step 2 – Primary drying: Via a vacuum, water or diluent is extracted from the compound.
• Step 3 – Final drying: The result is a very porous, stable and dry “lyo cake.”

The process typically takes two days, depending upon the compound and drug-delivery system.
 

Freeze-drying versus conventional drying

Unlike conventional drying methods, lyophilization protects the compound from denaturation caused by heat, since the product remains frozen throughout the process. Assuming proper storage, the shelf life of a product that has undergone lyophilization is up to three years versus a few days for the same drug in liquid form. Loss of biological activity is also less likely, because the freeze-drying process does not alter the compound.

The future of lyophilization

According to Visiongain (June 2010), it is estimated that half of the injectable drugs approved over the next five years will require lyophilization.

Vetter – expert and innovator

Vetter, whose expertise includes lyophilization and complex compounds, began freeze-drying products in 1981. Today, in collaboration with clients, Vetter’s specialists develop lyophilization cycles tailored to each product.

Dual-chamber technology. Vetter is the innovator of the Vetter Lyo-Ject® syringe and V-LK® cartridge dual-chamber systems. Lyophilized drug resides in one chamber; diluent in the other. Pushing the syringe plunger mixes the two with one stroke. A drug currently packaged in vials may be transferred to a dual-chamber syringe or cartridge when desirable, for example, to make the product more user-friendly as part of a lifecycle management plan.