Article review: Long-term physiochemical stability of diluted trastuzumab

Andy Watts and Maria Connolly, 10 July 2013

Muriel Paul*, Vitoire Vieillard, Ricardo Da Silva Lemos, Laurence Escalup, Alain Astier. Long-term physiochemical stability of diluted trastuzumab International Journal of Pharmaceutics 448 (2013), pp 101-104

The following table sets out how this paper either does or does not comply with the NHS (UK) guidance on the assessment of stability for biological products. The table uses the NHS guidance section headings and numbering to assist the reader.

Study Design

NHS Guidance Property to Evaluate Criteria for Evaluation Compliant (Yes/No) Comment
5.2 Containers Non-PVC Yes Freeflex®
5.3 Storage Refrigerated in absence of light Yes 5±3˚C
Room temperature (25±2˚C) No 20±2˚C
5.4 Concentration Low & high clinically significant Yes 0.8 and 2.4 mg/mL
5.5 Storage period 48 hours to 3 months No
5.6 Sampling strategy At least 4 sampling points in addition to the baseline (T=0) data. Yes Data is only presented for T = 0 and 180.
For studies ≥6 months, monthly sampling up to 3 months, then 3 monthly until study end. No No sampling at 2 months. Data only given for T = 0 and 180.
5.7 Sampling number Three independent batches No Two batches
Three replicates per batch No Two replicates
6 Testing protocol Minimum protocol to include:
a) colour, clarity, particulate No
b) pH No
c) chemical stability Yes
d) physical stability Yes
e) sub-visible particles Yes
f) biological activity No
g) Assessment of degradation Not applicable

The study being considered does not conduct sampling at required times for a 6 month study (5.6) and only data for two sampling points is provided (T = 0 and 180). The study does not contain sufficient numbers of independent batches or independent replicates (5.7) to meet acceptance criteria. Minimum required testing protocols (6) a), b) and f) were not performed.

Study Methods

NHS Guidance Property to Evaluate Criteria for Evaluation Compliant (Yes/No) Comment
7.1 Forced degradation A combination of some of:
a) change in pH No
b) realistic elevated temperature Yes 20±2˚C (elevated temperatures are generally 25–40˚C, but sample was stored for sufficient period (2 years) to observe degradation)
c) exposure to UV light No
d) agitation No
7.2 Visual characteristics Color, clarity and particulates No Not performed
7.3 pH Changes to pH No Not performed
7.4 Sub-visible particulates Evaluate particle levels over necessary range (1 – 100 μm) No Particle numbers not determined
7.5 Physio-chemical analysis Range of techniques to assess conformational, physio-chemical and aggregates (below size in 7.4). Should comprise a combination of:
a) SEC Yes
b) DLS Yes
c) CEX Yes
d) capillary or SDS electrophoresis No
e) circular dichroism No
f) FT IR Yes
7.6 Chemical a) HPLC Yes
b) UV Yes
c) mass spectrometry No
7.7 Biological activity Relevant to specific biological activity that enables product to achieve specific pharmaceutical action. Can comprise any of: No No biological evaluation performed
a) biochemical (ELISA)
b) cell based
c) animal

Study Methods Summary

The study did not evaluate visual characteristics (7.2) or changes in pH (7.3). Quantification of sub-visible particle numbers was not performed (7.4). Section 7.5 suggests a range of techniques to comprehensively assess the physical state of the protein. As such, not all listed techniques need to be performed, however the range of techniques employed do need to satisfy criteria for a comprehensive evaluation. The combination of techniques employed in this study can be considered to meet the criteria for a comprehensive evaluation of physical stability. For section 7.6 (which should also be considered in combination with some techniques performed as part of 7.5) the combination of techniques employed would not provide a comprehensive evaluation of chemical stability. By way of example, techniques employed would not detect minor changes in deglycosylation or glycation by small neutral sugars. No assessment of biological activity (7.7) is attempted. This is significant as changes in glycan profile (not determined in 7.6) are known to have impact upon biological activity.

© Maria Connolly, Andy Watts & Copies of this material can be made for the sole purpose of aiding in the assessment of the stability of the product presented in the study. Any copies must be made in full and retain this notice and reference to A Standard Protocol for Deriving and Assessment of Stability Part 2 — Aseptic Preparations (Biopharmaceuticals).