Used SP Scientific VirTis Freeze Dryers & Lyophilizers

Compatibility depends on the freezing point of the solvents and the volume of the samples. You'll need to identify the formulation's critical thermal thresholds, match them to the equipment's operational limits and evaluate condenser and solvent compatibility. VirTis systems are built to handle a wide range of formulations from simple aqueous solutions to complex organic solvents.

The condenser's main role is to create a cold surface on which solvent vapor sublimating from the product can deposit as ice, thereby maintaining a low chamber pressure, which is essential for the process.

Key factors to consider include:

• Freezing point and sublimation temperature: The condenser temperature must be significantly colder than the freezing point of the solvent being removed. It needs to be colder than the ice or frozen solvent's sublimation temperature in your product. The condenser should be at least 15°C to 20°C colder than the sample during primary drying to create a sufficient temperature differential and driving force for vapor flow.
• Solvent types in the formulation: For water-based solutions, condenser temperatures of -50°C to -85°C are common, with colder temperatures providing more robust vapor trapping. For organic solvents, you will require a much colder condenser. Temperatures of -85°C or lower might be necessary, since their freezing/triple points are too low to condense or freeze on a standard ice condenser, making them harder to trap.
• Desired drying rate and efficiency: A colder condenser creates a larger temperature and vapor pressure differential between the product and the condenser. This larger differential translates to a faster and more efficient removal of solvent vapor from the product chamber. If rapid drying is a priority, a colder condenser can help achieve it.

VirTis shelf systems are highly versatile — the distance between shelves is often adjustable, allowing users to configure the chamber for taller vials or diverse batch sizes:

• Vial sizes and capacities: VirTis stoppering shelf systems are designed to accommodate standard serum vials. The number of vials that can be placed on a shelf depends directly on the vial's diameter and the available shelf area and clearance.
• Tray configurations and shelf clearance: VirTis stoppering systems use shelves within the freeze-dryer chamber. The number of shelves and the resulting clearance between them are crucial for accommodating vials of different heights and for allowing the stoppering mechanism to function properly.

The stoppering mechanism is a pneumatic or hydraulic system that seals vials under vacuum before the chamber is opened. The shelves physically compress together, pushing pre-inserted slotted stoppers firmly into the vials. This feature is essential for preserving sample sterility and stability, especially in pharmaceutical and clinical applications.

The maximum load is determined by the unit's ice-condensing capacity, typically measured in liters over a 24-hour period. You can calculate your total batch volume and consult the specification sheet for the specific refurbished model you are viewing on the New Life Scientific website.