Analysis & Testing

Question 1

What is the EP specification for :-
a) Purified Water
b) WFI

Answer 1

Purified:-
TOC <500ppb
Conductivity <4.3ms @20’C
Nitrates <0.2ppm
Heavy Metals <0.1ppm
Aerobic Bacteria <100cfu/ml
Endotoxins <0.25 iu/ml

WFI:-
TOC <500ppb
Conductivity <1.1ms @20’C
Nitrates <0.2ppm
Heavy Metals <0.1ppm
Aerobic Bacteria <10cfu/100ml
Endotoxins <0.25 iu/ml

Question 2

What Guidelines relate to sampling of starting materials?

Answer 2

WHO Annex 4
Annex 8
ISO2859

Question 3

What are the general stability storage conditions according to ICH Q1?

Answer 3

25C 60% RH
30C 65% RH
40C 75% RH
Refrigerated 5C
Frozen -15C

Question 4

What are the dissolution stages of a tablet?

Answer 4

S1 6 units >= Q + 5%
S2 Further 6 units mean result of 12 >= Q no individual result less than Q - 15%
S3 Further 12 units mean result of 24 >= Q no 2?individual results less than Q - 15% and no result less than Q- 25%

Question 5

What validation tests would you perform for an ID test?

Answer 5

Specificity only

Question 6

What validation tests would you perform for an assay?

Answer 6

Everything but LOD/LOQ

Question 7

What is GCP vs GLP vs GMP?

Answer 7

GCP - good clinical practice (ICH E6) - protects trial participants and integrity of clinical trial data

GLP - Good Laboratory practice- applicable to pre-clinical lab and animal studies - ensures reliability of lab data

GMP - Manufacturing after approval

Question 8

What considerations are there for generating a new specification?

Answer 8

Development data
Pharmacopoeia
Toxicology data
Stability
Process capability

Tighter specifications may be applied at release to control impurities for example

Question 9

What are the specific considerations for a micro OOT / OOS?

Answer 9

Media - expiry, type, integrity, storage
Control Plates / EM Monitoring
Incubation Conditions
Correct Reagents

Likely source of organisms
Trend data
Cleaning

Question 10

What Annex relates to retain/reference samples?

What are the requirements for commercial vs IMP?

Answer 10

Annex 19

Commercial 1 year after expiry of product. Stored in UK or MRA country

IMP 2 years after the completion of the clinical trial. Can be stored on third country if defined in TA.

Question 11

What guidelines do we have relating to sampling?

Answer 11

Annex 8 Eudralex Volume 5 - Sampling of starting and packaging materials
ISO2859

Question 12

What is stress testing?

Answer 12

Typically done in development of a drug product to determine degradation products.

Temperatures increased in increments of 10 Degrees Celsius above accelerated conditions (50,60,60etc)

Question 13

What is photostability?

Answer 13

Determination of the affect of light on the drug product

Question 14

When is a test considered stability indicating?

Answer 14

When the attribute being tested is susceptible to change during storage and is likely to influence quality, safety and/or efficiency.

Question 15

What is considered acceptable timelines for pulling/ testing stability samples?

Answer 15

Nothing specific in ICH Q1 based on risk and should be documented as part of internal procedure,

WHO guidance that states 14 days

We use 14 days to pull and then should test as soon as possible with completion of all tests within 30 days.

Question 16

How would you set up a stability program for a new product?

Answer 16

Change Control
ICH Q1
Stability Protocol
Why ? - Shelf Life determination, New Product, Annual Set Down, Change
New Product 3mnths, 6mnths and then annual thereafter
Number of samples / strengths (Bracketing / Matrix)
Long Term Stability- 25^C 60% RH , 30^C 65% RH
Accelerated 40^C 75% RH
Climatic Zones

Question 17

What is dissolution testing and how is it performed?

Answer 17

Confirms release rate of drug

Basket / Padel
38C +_ 2C
PH specific to intended site of release

Samples taken typically analysed by UV / Vis or HPLC

Question 18

What are the requirements for method validation as outlined in ICH Q2?

Answer 18

Accuracy
Precision- Repeatability, Intermediate Precision
Specificity
Linearity
LOD / LOQ
Range
Robustness

Question 19

How is friability performed on tablets?

Answer 19

10/20 tablets
100 revolutions at 25th (4mins)
NMT 1% weight loss and no lamination or capping

Question 20

How does a HPLC work?

Answer 20

Physical separation where components are distributed between a mobile and stationary phase

Mobile phase circulates via pump (water /methanol or acetonitrile) through column containing stationary phase (silica +C18)

Separation occurs and analyses pass through flow cell to a detector and are Identified based on absorption of visible / uv light

Question 21

What analytical methods do we have to detect impurities?

Answer 21

Organic- HPLC, TLC, NMR

Inorganic- Wet Chemistry- Ashing or residue on ignition

Question 22

What is required to determine Precision of a method?

Answer 22

Repeatability- run minimum of 6 samples covering reportable range (eg 3 replicates 3 concentrations) work out RSD - SD / Mean x 100 - typically 2 % is acceptable for assay 5% impurities

Intermediate Precision- diff analysts / equipment

T-Test and

Work out RSD - SD / Mean x 100 - typically 2 % is acceptable for assay 5% impurities

Reproducibility - different laboratories (T-test)

Question 23

What is the expected regression coefficient for linearity?

Answer 23

0.999 (assay)
0.97 (impurities)

Question 24

How is the sterility test performed?

Answer 24

Aseptic condition
Samples taken start / middle/ end and after interventions
Number of sample depends on dosage form
Typically membrane filtration or direct inoculation
Media used is TSB / FTM - incubation is 14 days (TSB - 20-25 and FTM 30-35)

Question 25

When can we invalidate sterility results?

Answer 25

Micro monitoring of test shows a fault Testing procedure reveals a fault Growth in negative controls Fault with materials / techniques used for test

Question 26

What would you look at when auditing a laboratory?

Answer 26

Personnel- Training Premises / Equipment- Validation of equipment/ methods/ cleaning/water systems Documents- methods specifications logbooks Sample - storage, receipt and control OOS OOT retesting vs re sampling Data integrity- audit trails integration Stability- storing excursions protocols procedures

Question 27

What is ELISA?

Answer 27

Enzyme linked immunosorbant assay Measures antibodies, antigens, proteins Quantitative technique Specific antibodies bind to antigens and colour change indicates antigen binding

Question 28

What is a bioassay?

Answer 28

Determines potency of active by observing its effects on living organisms/ plants Lack of precision, rarely BP method Data analysed using standard curve

Question 29

When do you do hypothesis testing in an OOS / OOT and what are the conditions?

Answer 29

Phase 1B and Phase 2 Written approval prior to initiation- document must include: Root cause being investigated What samples are being tested Execution of testing How data will be evaluated Hypothesis testing can not replace original results

Question 30

If no assignable root cause found during OOS what can be done?

Answer 30

Retesting- of original sample or 2nd aliqout from same sample or if insufficient sample remains the procedure for resampling must be agreed The decision to retest is on scientific judgement- test plan approved before retesting occurs. Number or retests should be based on scientific principles and statistical review with regard to %RSD and repeatability should related to the value ms obtained during method validation (papers suggest 5,7,9) Retest is performed by different analyst.

Question 31

How does a Karl Fisher work?

Answer 31

It’s a titration using KF reagent which contains iodine. The iodine reacts with water and the titration is complete when all the water is consumed and excess iodine is detected.

Question 32

How does Loss on drying work?

Answer 32

Sample heated to vaporise liquid - the initial and final weights are used to determine percentage weight loss.

Question 33

What results would you report post OOS/OOT in the following circumstances: - ID of root cause at Phase I / II - ID of root cause at Phase II - No Assignable Causr

Answer 33

Follow guidance in MHRA OOS/OOT presentation - Invalidate original results and perform re-test - OOS confirmed - reject batch - Perform re-testing- number of retests need to be scientifically justified and statistically significant- based on Method capabilities ( 5,7,9)

Question 34

What would you do if you identify an outlier on your test results during OOS / OOT?

Answer 34

Refer to MHRA Guidance document- statistical analysis of outliers can for part of investigation. Typically more commonly used with Bioassays rather than chemical tests as in this case it can be used to reject data.