Aseptic Techniques: Production Areas

Aseptic Techniques: Introduction

• Aseptic techniques protect ophthalmic and parenteral products.
• They prevent microbial and particulate contamination.
• These techniques are also required to remove pyrogens and toxic bacterial products.
• This ensures environmental quality regarding microbial and dust particle contamination.
• Limiting contamination is vital to minimize product contamination.

Production Area Divisions

• Clean-up area
• Compounding area
• Aseptic area
• Quarantine area
• Packaging/labeling area

Clean-Up Section

• Walls and ceilings consist of film coating materials.
• Air should be free of dust and microorganisms, achieved with high-efficiency (95%) filters.
• Air should be replaced frequently, with 10-15 air changes per hour.

Compounding Section

• Contains stainless steel cabinets and counters.
• Used in the actual compounding process.
• Sterile conditions are less critical compared to aseptic areas.
• Measures are put in place to control dust generated by raw materials.
• This is especially while weighing and compounding.

Designing of Aseptic Area: General Design

• Designed and constructed for ease of cleaning.
• Promotes efficient operation, attractiveness, and comfort of personnel.

Clean Area Classification

• Clean areas are classified into grades A, B, C, and D.
• Grades are based on particulate quality of the environmental air during operation.
• All surfaces (floors, walls, ceilings) should be smooth
• Surfaces should be easy to clean, and disinfect.
• Constructed to minimize microbial and particulate contamination.

Floors

• Flexing and non-flexing materials are used in construction.
• Flexing floors use synthetic elastomers, commonly polyvinylchloride (non-slip grades).
• Polyvinylchloride flooring is easily repaired, cleaned, and relatively cheap.
• Non-flexing floors use hard inorganic filler substances in a matrix material.
• Concrete must be sealed adequately with chemical, solvent, and cleaning fluid-resistant materials.

Walls

• Must be made of non-inflammable or fire-resistant materials (stainless steel, glass, enameled steel, etc.).
• 1% of 8-hydroxy quinolone, or pentachlorophenol can be added to paint for fungal growth reduction.
• Epoxy resin and polyurethane paints prevent cracking and peeling.
• Should be flat, avoiding ledges and recesses.
• All pipes passing through walls should be sealed effectively and be flush fitting for easy cleaning.

Ceiling

• Should be solid with sealed joints.
• Light fittings and air grills need to be flush with the walls, and not hanging from ceiling to prevent contamination.

Doors

• Should fit flush with the walls.
• Should open towards the higher-pressure area for automatic closing.
• Well fitted to maintain positive pressure airflow and be self-closing.
• Limited in number.

Windows

• Should be flush with the walls.
• Furniture needs to be smooth, washable, and made of appropriate material other than wood.
• Provide illumination only, not for ventilation.
• Should be non-openable.

Services

• Light sources in clean rooms are ceiling-fitted.
• This reduces dust collection and avoid airflow pattern disturbances.
• Non-essential switches (room lighting) should be outside the clean area.
• Sinks and drains should not be present in aseptic procedure areas.
• Gas cylinders should be excluded; gases should be piped from outside.
• Traps need to be easily cleanable and installed with electrically heated disinfection devices.

Protective Clothing

• Prevents contamination from the body and everyday clothing.
• Designed to prevent contamination from the body.
• Must be sterilized by moist heat or ethylene oxide sterilization.
• Fresh sterile clothing should be provided each time someone enters the aseptic area.

Personal

• Skin scales released by operators are the main contamination source in clean areas.
• selected for parenteral product preparation must be neat and reliable.
• Should be in good health and free from dermatological conditions that might increase microbial load.
• Needs to be trained in good manufacturing practices and aseptic techniques.

Cleaning and Disinfection

• Used for the removal of microbial and particulate contamination.
• Cleaning agents include alkaline detergents, non-ionic and ionic surfactants.
• Use different types of disinfectants in rotation.
• This prevents resistant strain development in microorganisms.
• Use varying concentrations of quaternary ammonium compounds, sodium hypochlorite, ethanol, and formaldehyde as disinfectants.
• Cetrimide or chlorhexidine in 70% alcohol are suitable for skin disinfection.

Air Supply

• Should be filtered through High-Efficiency Particulate Air (HEPA) filters.
• HEPA filter needs to be positioned at the inlet of the clean room.
• The pre-filter may be fitted upstream of HEPA filters to prolong the life of the final filter.
• Air filtered from HEPA filters is claimed to be 99.97% free from microbial contamination.

Air Velocity Through Filters

• Filter area should be about 0.54 m/sec or (90+20 feet/min) .
• Air quality is evaluated using settle plates, microbial air samplers, or particle counters.
• HEPA filters are used in vertical and horizontal laminar airflow benches.
• Removes Dioctyphthalate (DOP) particles of size-0.3µm.

Laminar Air Flow Defined

• Airflow where the entire body of air within a designated space is uniform in both velocity and direction.
• Flow occurs along constant streamlines without turbulence.
• Over a horizontal surface may be thin layers all parallel to each other.
• Principle was first developed in the early 1960s.
• Unidirectional airflow helps in maintaining sterility, preventing cross-contamination, and reducing turbulence.
• The filtered air is claimed to be 99.97% free from microbial contamination.
• Level is based upon the removal of dioctylphthalate (DOP) particles of size 0.3 µm and larger.
• Air velocity at all parts of the filter should be 90 & 20 feet/min (0.54 m/sec).

Aseptic Compounding - Services Provided

• Clean air to critical sites (immediate aseptic compounding area).
• Constant airflow out of the work area prevents room air entry.
• Outward airflow removes contaminants from the work area.

Laminar Air Flow Equipment

• Delivers clean air in a vertical, horizontal, or curvilinear direction.
• Works on double filtration principle.
• Removes dust, pollen, mold, bacteria, and airborne particles of 0.3 micron or larger.
• Does not provide filtration to vapor or gases.
• HEPA filters are constructed of borosilicate microfibers in a pleated sheet form.
• Efficiency determined by aerosol tests.

Types of Laminar Air Flow: Horizontal Cabinets

• Named after airflow direction; air comes from above, changes direction and is processed horizontally.
• The constant flow of filtered air provides material and product protection.

Types of Laminar Air Flow: Vertical Cabinets

• Function as well as horizontal cabinets.
• Laminar air is directed vertically downwards onto the working area.

Air Supply Systems

• Air supplied to a clean room must be filtered through HEPA filters.
• Fiber glass paper is used as the filter medium.

Filter Composition

• The filter consists of a continuous corrugated separator between each pleat, sealed into a rigid metal frame.

Airflow Patterns

• General airflow patterns in clean rooms are unidirectional, non-unidirectional, and combined airflow.

Unidirectional Airflow

• Air moves with uniform velocity along parallel flow lines.
• Due to operating costs, it is not often used in pharmaceuticals.

Non-Unidirectional Airflow

• Air enters through filters, exits through outlet ducts, low on the wall or floor, away from air inlet.

Combined Airflow

• In pharmaceutical clean rooms, the background area is ventilated by non-unidirectional airflow.
• Critical areas are supplied with unidirectional airflow.
• A trend exists toward protecting critical procedures within combination clean rooms using isolator cabinets.

Uses

- Required for smaller items, e.g., particle sensitive electronic devices.
- Used for special operations in laboratories.
- Can be tailor-made to specific lab requirements.
- Used in the medical, pharmaceutical, electronic, and industrial sectors.

Advantages

- Spacious sterile area.
- Plant material can stay longer since the sterile area is not hot.
- Requires no moving parts or wear and has a simple design.
- Bigger flasks with wide lids can be used.

Sources of Contamination: Atmosphere

• The atmosphere cannot support microbial growth, but dust particles may carry soil microorganisms.
• Microbes occur in droplets expelled into the atmosphere by talking, sneezing, and coughing.
• Damp atmospheres have fewer microorganisms than dry ones. Contaminants are drawn down by moisture.
• The air in a cold store is usually free from microorganisms.
• The microbial count of air or the atmosphere is reduced by chemical disinfection, ultraviolet light, filtration, and gaseous agents.

Sources of Contamination: Operator

- Skin, hair, and clothing are potent sources of microbial contamination.
- Inadequate training is a factor.
- Skin microorganisms include Staphylococcus, lipophilic yeasts, and dermatophytic fungi.
- Poor personal hygiene results in skin coliforms and intestinal bacteria.
- Open wounds are a source of saprophytic and pathogenic microorganisms.
- Direct contact between hands and starting, primary packaging, and intermediate products is a source of contamination.
- Improper hygiene and unauthorized personnel entering production, storage, and product control areas.
- Insufficient gowning and protective equipment practices pose risks.

Sources of Contamination: Raw Materials

- Improper storage and handling lead to mix-ups or selection errors.
- Microbial or chemical contamination risks.
- Drugs from animal, plant, or natural sources are frequently contaminated with bacteria, yeasts, and molds.
- Degradation may occur because of extreme environmental conditions (heat, cold, sunlight, moisture).
- Water is a prime source of microbial and particulate contamination.
- Deionized, distilled, and water for injections are commonly used for preparation of different pharmaceuticals.
- Wrong labelling.
- Incorrect sampling and testing.

Sources of Contamination: Equipments

- Unsuitable design, size, corrosion-causing materials, or static material accumulation.
- Adulteration with lubricants, coolants, dirt, and sanitizing agents.
- Working and external surfaces of equipment may cause sedimentation of particles and droplets.
- Inadequate cleaning and sanitization due to equipment design.
- Inappropriate calibration and irregular service, and using defective equipment.

Sources of Contamination: Buildings and Facilities

- Inadequate size and organization of the space lead to selection errors.
- Mix-ups or cross-contamination between consumables, raw materials, or finished products.
- Poor filth and pest controls.
- Rough floors, walls, and ceilings.
- Absence of air filtration systems.
- Inadequate lighting and ventilation systems, poorly located vents, ledges, and drains.
- Non-directional airflow within production or primary packing areas.

Sources of Contamination: Manufacturing Process

- Absence of facilities required for manufacturing of a single product.
- Improper cleaning between batches minimizes product changeovers.
- Use of open manufacturing systems for exposing the product to the room environment.
- Improper zoning.
- Lacking area line clearance after each cleaning process and between each batch.
- Lack of cleaning status labelling on equipment and materials within the manufacturing facility.

Methods of Prevention of Contamination: Equipments

- Equipment may be sterilized or disinfected by heat, gaseous agents, or chemicals.
- Many tanks, containers, small equipment, and reaction vessels are sterilized by steam under pressure (autoclave).

Methods of Prevention of Contamination: Raw Materials

- Water may be treated by ultraviolet light, filtration, or stored at elevated temperature to discourage microbial growth.
- Apply heat treatment, filtration, recrystallization, irradiation, or other sterilization to reduce the microbial load.

Methods of Prevention of Contamination: Personal

- Restrict to authorized personnel and allow only trained workers to enter production areas.
- Maintain adequate personnel hygiene.
- Personnel should receive proper and regular hygiene training. This prevents activities that could hamper product quality.
- Manufacturing area personnel need to wear protective clothing (over-garments, hair cover, beard or mustache cover, and overshoes).
- Avoid touching exposed products or equipment in contact with the product with naked hands.

Methods of Prevention of Contamination: Access to Areas

- Access to production, packaging, and QC areas restricted to unauthorized workers.
- Personnel should gain access only via changing rooms.
- Materials should be accessed via specific routes (air locks).

Methods of Prevention of Contamination: Building Requirements

- Smooth, crack-free, easily cleanable floors, walls, and ceilings as they facilitate easy and effective cleaning.
- Windows or viewing panels should be closed (non-opening), fixed with wall panels, and sealed to prevent accumulation of dust.
- Design pipe work, ventilation, and light points to avoid recesses that are not easily cleanable.
- Stainless steel sinks should be present within production areas.

Methods of Prevention of Contamination: Cleaning and Disinfection

- In aseptic rooms, the differential air pressures should be higher than the adjacent controlled areas.
- Air filtration and air change rates should be set to attain the defined cleanroom class.
- Unidirectional (laminar flow) airflow should maintain sufficient velocity to sweep particles away from filling/closing areas.
- Ambient temperature and humidity should not be very high.
- Use ventilated cabinets, RABs, or isolator systems depending on facility/product risk assessment results.
- To achieve an absolute or partial barrier to contain microorganisms at their point of use.

Clean Area Classification: Standards

• British Standard Class 2 closely approximates US Federal Standard Class 10,000.
• Class 10,000 means no more than 10,000 particles per cubic foot of size 0.5 pm or greater were found in the measured area.
• British Standard Class 1 approximates US Federal Standard Class 100.
• Class 100 is applicable to aseptic areas.

Operation Types

• Operations are recognized by three main types of areas: black/dirty, grey/semi-clean, and white/clean.
• Black areas: Particle and microbial control is almost impossible.
• Grey areas: High hygiene and cleanliness operate, reducing microbial contamination.
• White areas: Environmental control is operational, and special protective clothing is worn by the operators.
• The area may be a Class-1 (aseptic) room, or a Class-II (clean) room.
• Class - II (clean) may have laminar flow units installed at terminal operation points.
• Terminal Operation Points i.e. filling lines.

Requirements for Sterility

• The sterile production unit must separate general manufacturing areas within the hospital pharmacy or factory.
• Access must be restricted to authorized personnel.
• The clean room should be away from corridors, stairways or lifts to impede bacterial and particulate transmission.
• The clean room should be the smallest size possible, bearing in mind operations needed and the number of people there.

Overview of aseptic techniques used to prevent contamination in pharmaceutical production. Covers clean-up, compounding, aseptic, and quarantine areas. Highlights air quality and material requirements for each area.