Every tablet, injection, and capsule begins its journey inside a carefully engineered facility. Behind the scenes, the materials used to build pharmaceutical plants play a critical role in product safety, hygiene, and efficiency. Poor material selection can cause contamination, corrosion, or equipment failure. UNIT 5 focuses on how pharmaceutical engineers choose construction materials, prevent corrosion, and design effective material handling systems.
In modern drug production, safe medicines depend as much on steel and glass as on chemistry.
Materials of Pharmaceutical Plant Construction
Why Material Selection Matters
The choice of construction material affects:
- Product purity
- Equipment durability
- Cleaning efficiency
- Cost and maintenance
- Regulatory compliance
Pharmaceutical environments demand materials that are non-reactive, corrosion-resistant, and easy to sterilize.
Factors Affecting Selection of Materials
Engineers evaluate several criteria before choosing materials:
- Chemical compatibility with drugs
- Mechanical strength
- Temperature resistance
- Corrosion resistance
- Smoothness and cleanability
- Cost-effectiveness
Proper selection reduces contamination risks and ensures long service life.
Corrosion: The Silent Threat to Equipment
What Is Corrosion?
Corrosion is the gradual destruction of metals due to chemical or electrochemical reactions with the environment. It can weaken equipment and contaminate products.
Even small rust formation may compromise pharmaceutical quality.
Theories of Corrosion
Chemical Theory
Direct reaction of metal with oxygen, acids, or moisture leads to corrosion.
Electrochemical Theory
Formation of anodic and cathodic areas causes electron flow and metal dissolution. This is common in moist environments.
Understanding these mechanisms helps engineers design preventive measures.
Types of Corrosion
Common Types Include
- Uniform corrosion
- Galvanic corrosion
- Pitting corrosion
- Crevice corrosion
- Stress corrosion
Each type damages equipment differently and requires specific control methods.
Prevention of Corrosion
Effective Strategies
- Protective coatings or paints
- Use of corrosion-resistant alloys
- Cathodic protection
- Proper drainage and cleaning
- Environmental control
Preventive maintenance saves costs and ensures safety.
Ferrous and Nonferrous Metals in Pharmaceutical Plants
Ferrous Metals
Ferrous metals contain iron and are widely used due to strength.
Examples
- Mild steel
- Cast iron
- Stainless steel
Among these, stainless steel is preferred because of its corrosion resistance and smooth surface.
Nonferrous Metals
Nonferrous metals do not contain iron and resist corrosion better.
Examples
- Aluminum
- Copper
- Brass
- Lead
They are used in specialized equipment but may react with certain chemicals.
Inorganic and Organic Non-Metals
Inorganic Non-Metals
Materials like glass and ceramics are chemically inert.
Uses
- Glass reactors
- Storage bottles
- Laboratory equipment
They resist corrosion but may be brittle.
Organic Non-Metals
These include plastics and polymers.
Examples
- PVC
- Polyethylene
- Teflon
- Rubber
They are lightweight, corrosion-resistant, and widely used in tubing and seals.
Basics of Material Handling Systems
What Is Material Handling?
Material handling refers to the movement, storage, and control of raw materials and finished products within a plant.
Efficient handling improves productivity and reduces contamination.
Objectives of Material Handling
- Reduce manual labor
- Prevent product damage
- Ensure hygienic transfer
- Save time and cost
Common Handling Systems
Equipment Used
- Conveyors
- Pumps
- Trolleys
- Forklifts
- Pneumatic systems
- Automated transfer systems
These systems allow smooth, contamination-free movement of materials.
Importance in Pharmaceutical Industry
Proper handling:
- Minimizes cross-contamination
- Maintains sterility
- Improves worker safety
- Enhances production efficiency
Modern plants increasingly rely on automation for precision and hygiene.