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Choosing the best vial washer for your lab
Vials are used in a wide range of industries including pharmaceuticals, medicine, fine chemicals, food science and agrochemicals. The hygiene protocols employed in the cleaning of vials is always of the utmost importance, for both patient safety and sample integrity.
High pressure jets of pure water
The most effective method of automated vial washing is to ‘scrub’ the vials with hot water using high pressure jets spraying the inside and outside of the vial. This effectively removes particulates, chemical contamination, bacteria and bacterial toxin residue.
The water that is used is clean enough to be injected. This water for injection (WFI) is expensive and therefore should be used as efficiently as possible. Vials come in different shapes and sizes and clearly less WFI is needed to wash a 2ml vial than a 100ml vial, so it is important that the washer adjusts to the size of vial being cleaned.
Types of automated vial washers
There are three main types of automated vial washer: in-line washers, batch washers and rotary washers.
In-line washers are popular at pharma plants that need a very high throughput of vials. They are large machines that are expensive to operate and often have high maintenance costs.
Batch washers wash vials by the rack and require an operator to load and unload the racks. It is estimated that people account for around 75% of microbial contamination in labware, so where high levels of cleanliness are required, batch washers are not the best option.
Rotary vial washers are ideal for high throughput situations where it is useful to have the vial washing automated. Depending on the size of washer, a typical low output could be 40 vials per minute for a small lab or for high speed automation for large pharmaceutical and biotech applications, up to 400 2ml vials per minute.
The design affects the efficiency and the sterility
Rotary washers fall into two radically different design philosophies – with or without penetrating nozzles that enter the vial neck during the washing process.
Rotary washers with penetrating nozzles generally use grippers spaced around the main turret to grab each individual vial. The vials are rotated through 180°, cleaned and dried as the turret rotates. This process is inefficient on a number of levels. Firstly, it requires hundreds of moving parts and springs, all of which must be closely monitored to ensure consistency. Secondly, it is expensive in terms of the energy consumed and the amount of water used. Thirdly, there is a risk that the penetrating nozzles can be misaligned, leading to chipped or scratched vials. Finally, it introduces the risk of particulate generation. Particulates can cause very serious patient conditions, including life threatening pulmonary embolism, mechanical block of the capillaries or arterioles, activation of platelets or subsequent generation of microthrombi or emboli.
Rotary vial washers without penetrating nozzles consist of rows of vials, radially positioned around a servo driven turret. These systems are compact, inexpensive, efficient, versatile and simple in construction and use. The design requires far less utility requirements than any other vial washer currently available. Each vial format has a dedicated, optimised set of change parts to ensure reliable, repeatable cleaning and can typically be changed in 10-15 minutes. All other changes are recipe driven via the machine’s operating interface where optimised parameters for the particular vial are stored; the operator simply selects the vial type to be washed.
Technically there are only two moving parts on the machine with no springs, clamps, chains or grease points, therefore the maintenance requirements are negligible. There are typically eight stations with six dedicated to a specific wash or dry process that spray water or air only when the vials are in the exact position. Time to spray is optimised for vial size and shape, ensuring the optimal use of WFI and energy.
The system operates with dedicated water manifolds with precision drilled holes rather than particulate generating, penetrating nozzles. The manifolds never move, the focused jet sprays cannot bend from the validated wash position and there are no needles to damage vials. The position and number of precision holes on each dedicated manifold is defined by the vial being washed. Tests have shown that high velocity, focused water jets are as effective, if not more effective, than penetrating nozzles.
Factors to consider when choosing a vial washer
When choosing a vial washer for your lab, be sure to consider:
- The footprint
- The volume of water used and the energy consumption
- How easy is it to adjust for different vial sizes
- The risk of particulate generation
- Maintenance requirements
- Its overall effectiveness at cleaning.
It is possible to purchase pre-sterilised vials, but in the long term this is an expensive option. Hand washing is not considered thorough and cannot be validated sufficiently to comply with regulatory requirements. Automated vial washers are a reliable method of sterilizing vials.
To find out more about vial washers or to discuss your requirements further, please contact Richard Lewis at firstname.lastname@example.org or +44 (0)1962 841092
Tags: External vial washers, rotary vial washer, rotary vial washing, Vial Washers