PEGP Exam cheat sheet

Mass balance: accumulation = in − out + generation − consumption; at steady state accumulation is zero, so in + generation = out + consumption.

Reynolds number Re = ρvD/μ; Re < 2100 is laminar, Re > 4000 is turbulent, and 2100–4000 is transitional flow in a circular pipe.

Fick's first law for diffusion: J = −D(dc/dx); flux is proportional to the concentration gradient and the diffusion coefficient.

Heat transfer through a wall: Q = UAΔT; for a cylinder, resistance R = ln(r2/r1)/(2πkL) and for a slab R = L/(kA).

Drying and evaporation rates follow the latent heat of vaporization; moisture content on a dry basis X = mass water / mass dry solids.

Particle size distributions are reported as D10, D50, D90; span = (D90 − D10)/D50, a smaller span means a narrower distribution.

NPSH available must exceed NPSH required by a margin to avoid cavitation in centrifugal pumps; NPSHa = (p_in − p_vapor)/(ρg) + static head − friction losses.

Powder flow is characterized by the flow function and angle of repose; a low Hausner ratio (bulk/tapped density near 1) indicates good flow.

Scale-up similarity criteria: geometric, kinematic, and dynamic similarity; full similarity is rarely achievable, so the controlling mechanism is held constant.

Mixing scale-up commonly holds tip speed (πND) or power per unit volume (P/V) constant; P ∝ N³D⁵ for turbulent impellers.

Scale-up ratio R = D_large/D_small; blending time typically scales with N⁻¹ and depends on impeller geometry and baffling.

Design of experiments (DoE) separates main effects from interactions; factorial, response surface, and Plackett-Burman designs are chosen by objective and budget.

Critical process parameters (CPPs) are identified from risk assessment and DoE, then linked to critical quality attributes (CQAs) in the control strategy.

Heat and mass transfer coefficients often do not scale linearly; pilot-scale confirmation runs are used to verify the chosen scale-up rule.

Scale-down models must reproduce the relevant hydrodynamic and residence-time distributions to be predictive of commercial performance.

Process robustness is demonstrated by operating within proven acceptable ranges (PARs) around set points without exceeding specification limits.

Distillation: relative volatility α determines separation ease; minimum reflux and minimum stages are found from McCabe-Thiele or Fenske equations.

Filtration: Darcy's law gives flow ∝ ΔP/(μR); specific cake resistance rises with compressibility, so higher ΔP may not improve throughput.

Fluidized bed dryers and granulators operate above minimum fluidization velocity, where pressure drop equals bed weight per unit area.

Centrifugation separates by settling velocity, which follows Stokes' law: v = d²(ρ_p − ρ_f)g/(18μ) in the Stokes regime.

Heat exchangers: LMTD correction factor F is applied for multipass units; countercurrent flow gives the highest effectiveness.

Tablet compression involves pre-compression and main compression stages; dwell time and punch geometry influence capping and lamination.

Chromatography performance is described by resolution, plate number N, and selectivity α; resolution depends on all three.

Clean-in-place design requires turbulent flow (Re > 10,000 typical target), adequate velocity (often ≥1.5 m/s), and validated contact time and temperature.

ICH Q7 covers GMP for active pharmaceutical ingredients; ICH Q8, Q9, and Q10 cover pharmaceutical development, quality risk management, and the quality system.

ICH Q1A stability guidance specifies long-term, intermediate, and accelerated conditions; data support shelf life and retest periods.

A change control system evaluates impact on product quality, regulatory filings, and validation status before implementation.

Deviation and CAPA systems require root cause analysis (e.g., 5-Why, fishbone), corrective action, and effectiveness checks.

Annual product quality review (APQR) is required for marketed products and covers batches, deviations, complaints, and changes.

Regulatory submissions use the CTD format: Module 1 regional, Module 2 summaries, Module 3 quality, Module 4 safety, Module 5 efficacy.

Data integrity follows ALCOA+ principles: attributable, legible, contemporaneous, original, accurate, plus complete, consistent, enduring, available.

Out-of-specification results are investigated per a written procedure before any retest or resample decision is made.

Premises must be designed with defined air cleanliness zones; unidirectional airflow protects critical exposed product areas.

Personnel flow and material flow are separated to prevent cross-contamination; gowning is graded to the cleanroom class.

Batch records must be contemporaneous; corrections are made with a single line, initials, date, and reason, never by overwriting.

Equipment cleaning validation demonstrates removal of product residues, cleaning agents, and microbial contamination to defined limits.

Water systems: purified water and water for injection have specified conductivity, TOC, and microbial limits; loops are continuously circulated.

Environmental monitoring includes viable and non-viable particles, surface sampling, and personnel monitoring at defined frequency.

Line clearance before each batch prevents mix-ups; all previous materials, documents, and components are removed and verified.

Complaint handling and recall procedures must be written, tested, and capable of rapid execution.

The V-model links user requirements to DQ, IQ, OQ, and PQ; each phase has documented acceptance criteria.

Design qualification (DQ) verifies the design meets user requirements before purchase or construction.

Installation qualification (IQ) confirms equipment is installed per specification; operational qualification (OQ) tests function across operating ranges.

Performance qualification (PQ) demonstrates consistent performance under production conditions, often with three consecutive successful batches.

Process validation lifecycle per FDA guidance: Stage 1 process design, Stage 2 process qualification, Stage 3 continued process verification.

Cleaning validation acceptance limits are derived from health-based exposure limits (HBEL/PDE) or traditional 1/1000 dose and 10 ppm criteria.

Computer system validation follows GAMP 5 categories and requires traceability from requirements to test evidence.

Revalidation is triggered by changes to equipment, process, or materials that could affect product quality.

Potent compounds are handled under containment with occupational exposure limits (OEL) and acceptable daily exposure (ADE) values.

Dust explosions require fuel, oxygen, ignition, dispersion, and confinement; combustible dust hazards are assessed per NFPA standards.

Solvent handling follows flash point and autoignition temperature data; flammable liquids are stored and bonded/grounded to prevent static ignition.

Waste streams are segregated (aqueous, organic, solid, hazardous) and characterized before disposal per local environmental regulations.

Process hazard analysis (PHA) methods include HAZOP, what-if, and failure mode and effects analysis (FMEA).

Pressure relief and emergency shutdown systems are designed and verified for credible worst-case scenarios.

Chemical exposure monitoring uses air sampling compared with occupational exposure limits; results drive engineering controls first.

Spill prevention, secondary containment, and wastewater pH/COD limits are typical permit conditions for pharmaceutical sites.