Chapter 12 Transfer Procedures By the end of this chapter, you will be able to: l Explain the term transfer process l Name two types of sanitisation methods often used l Describe the spray and wipe technique l Explain the transfer process and give some examples of items that may be transferred Introduction This chapter examines techniques used to transfer items into clean rooms and critical work zones. We will look at how to effectively use the spray and wipe technique and how we physically transfer items using trays and hatches. The Transfer Process The transfer process is the process used when anything is transferred from an area of lower environmental grade to one of higher standard. It isn t just the transfer of products to the critical zone and includes transfer of other items such as the examples below. l Equipment l Bin liners l Clean room furniture, e.g. trolleys, stools, portable benches l Cardboard boxes or containers l Sharps bins Important! The transfer process involves complete surface disinfection prior to the introduction of an item into hatches of a clean room or isolator. The contact time should be clearly stated in the SOP, checked and maintained in practice. Chapter 12: Transfer Procedures 1
Aseptic Processing Sanitisation (This is the term used in the pharmaceutical industry to describe cleaning and decontamination) Product components must be sanitised as part of the transfer process using approved sterile agents. Sanitisation is generally done in one of 2 ways: l Spray and wipe l Gas sanitisation. For the sanitisation process to work effectively against micro-organisms, starting materials are sprayed and wiped. The usual procedure is to spray, wipe the surface then spray again. However as long as one decontamination includes a spray and wipe combination this is satisfactory. Alcohol solutions are usually used for the spraying process. It has been tried and tested over many years and it rapidly destroys a wide range of micro-organisms. The most common alcohols used are 70% v/v ethanol (sometimes referred to as 70/30 ethanol or IMS) or isopropyl alcohol 70% or IPA. A clean part of the wipe must be used each time it is wiped across the surface. For maximum effectiveness the alcohol needs a contact time of 2 minutes. Alcohol evaporates quickly to leaves no residues which makes it suitable to use with most surfaces. 2 Chapter 12: Transfer Procedures
Chapter 12 Transfer Procedures Spray and Wipe Here is a summary of the advantages and disadvantages of spraying and wiping as stand alone activities. Spraying Advantages Quick Easy Gives good coverage Can be controlled so packaging is not over wetted or damaged Disadvantages High vapour levels Dependant on operator performance Spores not killed (although they may be rinsed off) Wiping Advantages Spores and particulates physically removed from the surface Easy Lower vapour levels Disadvantages High dependency on operator performance Wipes need to be turned and changed frequently Wipes need to be stored correctly So you can see that spraying or wiping by itself isn t as effective as combining the two operations. The spray and wipe method is very dependent on good practice from the operator so it is vital that good training and validation takes place. l To carry out the disinfection of assembled work, the operator should be gowned correctly. l Staff should wear disinfected gloves to carry out the transfer process. l Check gloves frequently for holes and tears l Spray gloves frequently l Remember to immediately apply alcoholic hand rub as soon as gloves are removed. Chapter 12: Transfer Procedures 3
Aseptic Processing Gas Sanitisation Isolators and starting materials can be sanitised with a gaseous agent, usually hydrogen peroxide or peracetic acid. Clean and disinfect work surfaces to be used Disinfect and wipe a second work tray to be used NB-Units may also use an autoclave sterilised tray An example of a gassing isolator with the front screen open l Gas sanitisation involves the vaporisation of the gas into the cabinet using a specialist machine. l Once the whole of the cabinet has been filled with the gas and all surfaces covered, the machine switches to pumping clean air through. l It is this process of air removing the gas from the surface that sanitises it. Effective gaseous biocides include: l Ethylene oxide (not used in isolators-it can be dangerous and explosive) l Formaldehyde vapour (rarely used for isolators because of toxicity issues) l Peracetic acid vapour l Hydrogen peroxide vapour Transferring components Checks! Before the sanitisation process begins all items in the tray should be checked to ensure that they match with the assembly check already carried out. (See Chapter 11) All the items should be separated into single units and vial caps and infusion wrappers removed, depending on your local procedure. All components should be free from dirt, dust, cracks or chips. Items should be sprayed and wiped to ensure that all surfaces are wetted. Each item should be taken in turn and all surfaces wiped with sterile alcohol wipes using a uniform wiping action. 4 Chapter 12: Transfer Procedures
Chapter 12 Transfer Procedures Note: The same surface of the wipe should not be used twice. You should not use a rubbing or circular action! (You are not cleaning windows!). Place wiped items into the second tray Isolator hatches inner surfaces need to be disinfected using spray/wipe before a tray is placed inside. When all the items have been wiped and placed in the second tray the whole tray and contents should be oversprayed as it is moved into the clean room hatch. Don t forget to spray the base of the tray. Remember to spray the tray surface that your hand was last in contact with. The transfer hatches inner surfaces need to be disinfected using spray/wipe before the tray is placed inside. The transfer hatch door should then be closed and the tray left in the hatch for 2 minutes minimum contact time. Note: If your hands touch anywhere on the hatch, then you must spray that too! The Isolator transfer hatches are usually timed through a control panel. Remember. During the transfer process you should pay particular attention to the following: l Paper based products harbour more micro-organisms than plastic ones. l Labels can lift and expose the adhesive at a later stage (glue is a known source of microbial contamination). l Edges, folds and creases need to be straightened and wiped to ensure efficient sanitisation. l All surfaces should be sufficiently wet-not soaked l The worksheet should be intact and sealed in a plastic bag. Operators must be able to read it! l Spray your gloves frequently Chapter 12: Transfer Procedures 5
Aseptic Processing Summary of the transfer process Transfer to Critical Zone This is the transfer from the hatch into the critical zone. The critical zone is the controlled workspace where aseptic manipulation takes place Two stages in sanitisation will have taken place before transfer: l Primary disinfection using wiping and spraying in the support rooms. l Secondary disinfection as part of the transfer process. Contact Time l The tray must also have been left for at least 2 minutes in the transfer hatch. l Sufficient contact time must be allowed during all parts of the sanitisation process. The tray is removed from the transfer hatch and the tray and contents are sprayed before placing onto the Laminar Air Flow Cabinet surface. 6 Chapter 12: Transfer Procedures
Chapter 12 Transfer Procedures In the isolator unit the container has been sprayed into the transfer hatch and is waiting for transfer into the critical zone Transfer Out of Critical Zone Before transfer out of the critical zone the following should be observed: l Waste should be disposed of by following the correct procedure. l On completion of a product all items for checking must be reconciled, and placed in the transfer tray. l Final products should be wiped to remove any external chemical contamination before leaving the isolator or LAFC. l Components for checking and finished products must be kept together. l Items leaving the critical zone are not subject to a time delay and can be placed directly in the hatch. l If final product is placed in the same hatch as when entering the room, make sure there are no incoming products in the hatch. l All products should be moved to labelling and checking l All surfaces within the critical zone should be cleaned and wiped with alcohol. Chapter 12: Transfer Procedures 7
Aseptic Processing Test Yourself Can you remember what you should pay particular attention to during the transfer process? Test Yourself Fill in the blanks in the following sentence: The critical zone is... where........ takes place. Workflow There may be more than one product being made at a time in an aseptic unit. Products need to be separated in some way so that there is no confusion about the starting materials, components, worksheets and labels which could lead to confusion and errors. If the same facilities are used for different product types: l Activities must be segregated by time. l Specific cleaning arrangements should be set up to avoid cross contamination. l Consideration should be given to permanently separating product types by the use of a separate cleanrooms or isolators. All components for the product should be assembled prior to processing Manipulations should be undertaken in one operation. There should not be a break in the process to add further components especially in the critical zone. (Remember: The critical zone is the controlled space where aseptic manipulation takes place.) Trays should not be overfilled (boxes with lids can be used as an alternative to prevent items falling out). Labels should be adequately segregated and reconciled to avoid mislabelling. When all the products are completed they should be identified by a label. Note: Products made at the same time (using the same worksheet) should be kept together. 8 Chapter 12: Transfer Procedures
Chapter 12 Transfer Procedures Activity Make sure you watch the following videos at: http://www.medslearning.leeds.ac.uk/pages/aseptics/videos.html and then refer to your local procedures: l Spray and Wipe-Spraying video 6 l Spray and Wipe-Wiping video 7 If there are any variations in your local procedures, make a note of them below and discuss with your supervisor. Spraying: Wiping: Chapter 12: Transfer Procedures 9
Aseptic Processing Questions Q1 What are the advantages of the spray and wipe processes? Spraying: Wiping: (4) (3) Q2 Describe how the Gas Sanitisation process works. (4) 10 Chapter 12: Transfer Procedures
Chapter 12 Transfer Procedures 1. Q3 When transferring items into the clean room, what are the 6 stages of the transfer process? 2. 3. 4. 5. 6. Chapter 12: Transfer Procedures 11
Aseptic Processing Q4 Why should products of different types be segregated? (2) Q5 Into critical zone: How long should the tray be left in the transfer hatch when transferring into and out of the critical zone? Out of critical zone: 12 Chapter 12: Transfer Procedures