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Glass Delamination
Study in Pharmaceutical containers
As per USP <1660>, Glass delamination may be described as the appearance of thin flexible flakes of glass (or lamellae) that can range in size from <50 µm to 200 µm in a drug product solution. This is a serious quality issue and can result in a product recall. The appearance of glass lamellae is a lagging indicator of a strong interaction between the drug product and the inner surface of the glass. Delamination is thus an indicator of glass corrosion.
Tests for delamination combine the visual examination of the solution, a microscopic examination of the vial's internal surface and stress testing to assess the delamination potential of the glass.
Why does glass delamination occur?
The process of forming tubular vials and ampuls requires heating. During formation of the neck and particularly the base, the temperature of the inner surface of the containers can exceed the evaporation point of some of the glass components such as alkali borates. In some cases, the glass can phase separate during forming, creating non-homogenous surface chemistry on the interior of the container. Also, the inner surfaces of glass ampuls, vials, and bottles may undergo additional treatments causing change in glass surface chemistry and uniformity.
The key factors that influence glass surface durability of containers manufactured from Type I glass are:
- Manufacturing conditions, such as:
- Type of glass (composition),
- Forming temperature,
- Time of exposure to heat,
- Annealing conditions, and
- Coatings / Treatments.
- Post-manufacturing operations, such as:
- Storage in humid conditions and
- Depyrogenation in the presence of water vapor, and
- Terminal sterilization via autoclaving
- Drug Product Composition and Characteristics, such as:
- pH
- Organic acids
- Chemistry of Buffer used
- Ionic strength
- Storage conditions
IMPORTANT: The Glass Delamination Study is required to be carried out by the drug manufacturer to study each drug formulation’s interaction with the glass container at the intended storage condition or it’s equivalent accelerated condition.
CLL’s Solutions for Glass Delamination Study:
CLL uses a combination of techniques to carry out Glass Delamination Studies:
- Predictive Screening of Glass container
- Aggressive Screening of Glass container / Stress Testing
- Drug product interaction with Glass Container study – Accelerated conditions
A final Comprehensive Report is submitted to client with following details:
- Evaluation of Vials pre- and post- Stress Testing as per USP <1660> (3 stress solutions);
- Analytical Method Development and Validation data for ICP-MS for elemental analysis in Drug Product (Si, Pb, B, As, Ba);
- Evaluation of Final Drug Product filled container against Water filled control @ Accelerated Climate Conditions (ACC) time and temperature as per ICH – 6 month study.
The final glass delamination report allows customers to make decisions on:
- Glass container suitability determination for drug product
- Vendor Qualification
- Regulatory Submission
- Market recalls
Regulatory References: USP <1660>, <660>
Turnaround Time: 3 to 4 weeks for
- Delamination Predictive Screening: 2 Weeks
- Delamination Aggressive Screening: 2 Weeks
- Delamination Accelerated condition (3-6Months) Interaction Study: 3 to 6 months