Chapter 25

25.1 Introduction

The concepts discussed in the previous chapters become most valuable when applied to a practical facility design. This chapter presents a comprehensive case study of a multi-product Oral Solid Dosage (OSD) pharmaceutical manufacturing facility, demonstrating how cubicle classification, HVAC zoning, pressure cascades, material flow, personnel flow, and contamination control are integrated into a GMP-compliant facility.

The objective is to illustrate how engineering principles, Quality Risk Management (ICH Q9), and global GMP requirements can be combined to create a robust pharmaceutical manufacturing environment.

This case study is intended as a training reference for:

Pharmaceutical Engineers
Production Managers
Validation Engineers
HVAC Engineers
QA Professionals
Consultants
Regulatory Auditors
Pharmaceutical Students

25.2 Project Overview

Facility Description

Parameter	Description
Facility Type	Oral Solid Dosage (OSD) Manufacturing
Products	Tablets and Capsules
Manufacturing Type	Multi-product, campaign-based
Compliance Standards	WHO GMP, US FDA, EU GMP, PIC/S, ISPE
Manufacturing Capacity	500 million tablets/month (example)
HVAC System	Central AHU with dedicated process AHUs
Building Management	BMS integrated

25.3 Design Objectives

The facility was designed to:

Prevent cross-contamination.
Maintain product quality.
Support efficient production.
Provide logical material and personnel flow.
Ensure regulatory compliance.
Facilitate qualification and maintenance.
Allow future expansion.

25.4 Manufacturing Process Flow

Raw Material Receipt
          │
          ▼
Raw Material Warehouse
          │
          ▼
Sampling
          │
          ▼
Dispensing
          │
          ▼
Sifting
          │
          ▼
Granulation
          │
          ▼
Drying
          │
          ▼
Milling
          │
          ▼
Blending
          │
          ▼
Compression
          │
          ▼
Coating
          │
          ▼
Inspection
          │
          ▼
Packaging
          │
          ▼
Finished Goods Warehouse

The process follows a unidirectional flow, eliminating backtracking and reducing contamination risks.

25.5 Facility Layout Concept

Warehouse
     │
Sampling
     │
Dispensing
     │
Granulation
     │
Drying
     │
Milling
     │
Blending
     │
Compression
     │
Coating
     │
Inspection
     │
Packaging
     │
Finished Goods

The layout minimizes product movement and simplifies material logistics.

25.6 Cubicle Classification Matrix

Manufacturing Area	Classification	Pressure Strategy	Typical ACH	Temperature	RH
Sampling	Controlled GMP Area	Positive	20–25	22°C	45–55%
Dispensing	Controlled GMP Area	Positive	20–30	22°C	45–55%
Granulation	Controlled Manufacturing	Positive	20–30	22°C	40–50%
Drying	Controlled Manufacturing	Positive	20–25	22°C	Process dependent
Milling	High Dust Control Area	Contained / risk-based	25–35	22°C	35–45%
Blending	Controlled Manufacturing	Positive	20–30	22°C	40–50%
Compression	Controlled Manufacturing	Positive	20–30	22°C	35–45%
Coating	Controlled Manufacturing	Positive	20–30	22°C	40–50%
Inspection	Controlled Area	Positive	15–20	22°C	45–55%
Packaging	Controlled Area	Positive	15–20	22°C	45–55%

Values shown are representative examples and should be confirmed through process development, HVAC design, and Quality Risk Management.

25.7 HVAC Zoning

Dedicated HVAC zoning was selected to improve contamination control.

AHU	Area Served
AHU-1	Sampling & Dispensing
AHU-2	Granulation
AHU-3	Compression
AHU-4	Coating
AHU-5	Packaging
AHU-6	Warehouse & Corridors

Design Benefits

Reduced cross-contamination.
Easier maintenance.
Improved balancing.
Simplified qualification.
Greater operational flexibility.

25.8 Pressure Cascade Design

Coating
 +35 Pa
     │
Compression
 +30 Pa
     │
Blending
 +25 Pa
     │
Granulation
 +20 Pa
     │
Dispensing
 +15 Pa
     │
Corridor
 +10 Pa

The pressure cascade maintains airflow from cleaner to less clean areas, reducing dust migration.

25.9 Material Flow

Receiving
     │
Warehouse
     │
Sampling
     │
Dispensing
     │
Manufacturing
     │
Packaging
     │
Finished Goods
     │
Dispatch

Best Practices

Dedicated material corridors.
Material Airlocks (MALs).
Barcode-based identification.
Quarantine and released material segregation.

25.10 Personnel Flow

Main Entrance
      │
Locker Room
      │
Primary Change Room
      │
Secondary Change Room
      │
Personnel Airlock (PAL)
      │
Manufacturing Area
      │
Exit through De-gowning

Personnel movement is separated from material flow to minimize contamination.

25.11 Airlocks and Pass Boxes

Personnel Airlocks (PAL)

Controlled entry.
Door interlocking.
Pressure monitoring.
Gowning area.

Material Airlocks (MAL)

Raw material transfer.
Intermediate transfer.
Packaging component transfer.

Pass Boxes

Static pass boxes for documents and low-risk materials.
Dynamic pass boxes for higher-risk transfers where justified.

25.12 Environmental Monitoring Strategy

Parameter	Monitoring
Temperature	Continuous
Relative Humidity	Continuous
Differential Pressure	Continuous
Airborne Particles	Risk-based
Dust	Process-specific
Surface Monitoring	Scheduled
Air Sampling	Risk-based

Monitoring results are reviewed monthly for trends.

25.13 Qualification Strategy

Lifecycle Qualification

URS
 │
 ▼
DQ
 │
 ▼
IQ
 │
 ▼
OQ
 │
 ▼
PQ
 │
 ▼
Routine Monitoring
 │
 ▼
Periodic Requalification

Qualification Activities

HVAC qualification.
Pressure mapping.
Temperature mapping.
RH mapping.
HEPA integrity testing (where applicable).
Airflow visualization.
Environmental monitoring verification.

25.14 Risk Assessment Summary

Risk	Likelihood	Impact	Control Measure
Cross-contamination	Medium	High	Dedicated HVAC zones and pressure cascade
Dust migration	High	High	Local exhaust and containment
Material mix-up	Medium	High	Barcode system and line clearance
Pressure failure	Low	High	Continuous monitoring and alarms
Environmental excursion	Medium	Medium	Trend analysis and CAPA

25.15 Contamination Control Strategy (CCS)

The CCS included:

Scientific cubicle classification.
Risk-based HVAC zoning.
Pressure cascade verification.
Controlled material and personnel flow.
Environmental monitoring.
Cleaning and disinfection program.
Qualification and validation.
Preventive maintenance.
Change control.
CAPA integration.

25.16 Building Management System (BMS)

The facility implemented a BMS to continuously monitor:

Temperature
Relative Humidity
Differential Pressure
AHU Status
Filter Alarms
Fan Status
Trend Reports

Critical alarms were routed to Engineering and QA for prompt response.

25.17 Inspection Readiness

The facility maintained inspection readiness through:

Annual internal GMP audits.
Quarterly HVAC reviews.
Periodic smoke studies.
Routine environmental monitoring review.
Annual requalification.
Mock regulatory inspections.
CAPA effectiveness checks.

25.18 Challenges Encountered

Challenge	Resolution
Pressure fluctuation in compression room	HVAC balancing and recalibration
High dust during milling	Upgraded dust extraction and containment
Frequent door opening	Access control and operator training
RH variation in coating room	Improved humidity control strategy
Material congestion	Redesigned staging areas and material flow

25.19 Lessons Learned

Risk-based design minimizes costly modifications later.
Dedicated HVAC zoning improves operational stability.
Pressure cascades require continuous monitoring.
Material and personnel segregation significantly reduces contamination risk.
Early involvement of QA, Engineering, Production, Validation, and Maintenance improves facility performance.
Preventive maintenance and trending reduce unexpected failures.

25.20 Performance Outcomes

Performance Indicator	Result
Pressure Cascade Compliance	>99% within limits (example)
Environmental Monitoring Excursions	Reduced after optimization
Internal Audit Observations	Significantly reduced
Regulatory Inspection Outcome	Successful GMP inspection
HVAC Downtime	Reduced through preventive maintenance
Product Rejection Due to Environmental Issues	No significant trend observed

Illustrative results shown for training purposes; actual performance will vary by facility.

25.21 Best Practices Demonstrated

✔ Risk-based cubicle classification

✔ Dedicated HVAC zoning

✔ Scientific pressure cascade

✔ Segregated material and personnel flow

✔ Continuous environmental monitoring

✔ Integrated Building Management System

✔ Lifecycle qualification

✔ Preventive maintenance

✔ Comprehensive Contamination Control Strategy

✔ Strong Quality Risk Management

25.22 Case Study Checklist

Checkpoint	Status
Facility layout optimized	☐
Cubicle classification justified	☐
HVAC zoning documented	☐
Pressure cascade verified	☐
Material flow segregated	☐
Personnel flow controlled	☐
CCS implemented	☐
Qualification complete	☐
Environmental monitoring active	☐
Inspection readiness maintained	☐

25.23 Integrated Facility Design Model

Quality Risk Management
         │
Facility Layout
         │
Cubicle Classification
         │
HVAC Design
         │
Pressure Cascade
         │
Material Flow
         │
Personnel Flow
         │
Environmental Monitoring
         │
Qualification & Validation
         │
Contamination Control Strategy
         │
Continuous Improvement

Chapter Summary

This case study demonstrates how pharmaceutical cubicle classification is successfully implemented in a multi-product OSD manufacturing facility by integrating engineering design, Quality Risk Management, HVAC zoning, pressure cascades, material and personnel flow, qualification, environmental monitoring, and contamination control into a unified facility strategy. A lifecycle approach supported by continuous monitoring, preventive maintenance, and inspection readiness helps ensure consistent product quality, operational efficiency, and sustained GMP compliance.

Key Takeaways

A successful OSD facility begins with a risk-based design supported by documented engineering decisions.
Cubicle classification, HVAC zoning, and pressure cascades must function together to control contamination.
Segregated material and personnel flows reduce the risk of mix-ups and cross-contamination.
Continuous environmental monitoring, qualification, and preventive maintenance help maintain the facility in a validated state.
Collaboration between Engineering, QA, Production, Validation, Maintenance, and EHS is essential for long-term operational excellence.

Next Chapter

Chapter 26 – Practical GMP Checklists for Pharmaceutical Cubicle Classification, including comprehensive audit checklists for cubicle design review, HVAC systems, pressure cascade verification, environmental monitoring, qualification readiness, validation readiness, inspection readiness, and GMP compliance, providing practical tools for engineers, QA teams, auditors, and pharmaceutical manufacturing professionals.

About the Author

Ramesh Palav is a pharmaceutical manufacturing professional with 21+ years of experience in Oral Solid Dosage manufacturing, production operations, GMP compliance, qualification, validation, QMS and operational excellence. Through Pharma Manufacturing Hub, he shares practical industry knowledge with pharmaceutical professionals, students and manufacturing leaders.

Design of Cubicle Classification for a Pharma Oral Solid Dosage (OSD)facility.