Creating superior surface properties with coatings

To meet the rising demand for superior packaging solutions to protect sensitive formulations, SCHOTT has significantly expanded its coating capabilities

Packaging has become an integral part of the drug, which means that pharma companies and packaging suppliers have to thoroughly evaluate the specific requirements of the patient, the product and the process before choosing the packaging.

This holistic “three Ps” approach by SCHOTT is especially important when it comes to finding the right container for highly sensitive formulations such as large, biotech-based molecules or radioactive drugs.

Owing to their complex molecular structures, innovative and advanced packaging solutions are required. This is when coatings come into play; they can improve the functional barrier properties of the inner container surface to protect the formulations and, subsequently, ensure patient safety.

With the rising interest in biotech drugs, SCHOTT has further invested in coating capabilities at its production facility in Müllheim, Germany. The site also serves as a competence centre for vials. The coatings can create, for example, a functional barrier to ensure that the drug formulation and container surface do not interact, or hydrophobic properties, which is a characteristic that’s especially recommended for lyophilisation.

The company has been producing coated vials for more than 20 years. The knowledge and experience gained during this time has been incorporated into the development of new coating capabilities and the implementation of high levels of automation, as well as additional measures to reduce glass-to-glass contact and particle load. The expansion, in operation from early 2018, will allow SCHOTT to double its production capacity.

To internally coat hollow bodies, the company has developed a unique process: Plasma Impulse Chemical Vapour Deposition (PICVD) technology. It is used to apply a razor-thin, transparent and non-porous film to the internal container surface.

The coated vials, generally Type I vials, are suitable for a wide variety of common processing steps within the pharmaceutical industry, from washing, autoclaving and sterilisation to depyrogenation at temperatures of up to 350 °C. Just like non-coated vials, they can be filled, sealed and inspected in the same way.

Moreover, the advanced PICVD coating process offers the advantage of being silicone-free. As the hydrophobic layer is covalently bonded to the glass matrix, the risk of silicone droplets detaching from the surface and interacting with the drug is eliminated to ensure patient safety.

TopLyo vials for efficient lyophilisation

SCHOTT TopLyo vials are particularly recommended for lyophilisation because of the 40 nm thin, stable and hydrophobic interior Si-O-C-H surface that’s applied using PICVD coating technology.

The hydrophobic properties ensure that the adhesion of substances to the surface of the containers is reduced, which simulates the so-called lotus effect: liquid residues are drawn together to form individual drops that, consequently, minimise the residual volume. This reduces the need to overfill the vials in the first place, which delivers significant cost benefits for pharma companies.

The coated SCHOTT TopLyo vials have a contact angle for water of roughly 100 degrees to allow for complete removal of the drug after reconstitution.

Furthermore, the coating offers better cosmetic results as there is less fogging during and less disruption of the cake after the lyophilisation process. Compared with siliconised vials, the SCHOTT TopLyo vials demonstrate reduced protein aggregation owing to the non-porous, covalent bond between the glass matrix and the coating layer.

Type I plus: an inert SiO2 layer

Sensitive drug formulations require innovative packaging solutions to ensure that they remain stable throughout their shelf-lives. SCHOTT Type I plus vials possess a 100–200-nm thin internal SiO2 coating to significantly reduce the interaction between the drug product and the container surface.

Consequently, the coating ensures that leaching from the packaging is reduced, which could potentially limit the efficacy of the drug. The coated vials possess the purity and inertness of a quartz-like inner surface and deliver pharmaceutical properties that comply with all current standards (Ph. Eur., USP and JP, for example).

The barrier layer comes with multiple benefits: it prevents depletion of the glass container by the drug formulation and also acts as a diffusion barrier for all the other elements of the glass matrix. Moreover, the leaching of metallic ions (sodium, calcium, boron, silicon and aluminium) is avoided and suppressed to a level below respective detection limits (proven by EP 3.2.1).

In an evaluation test, 11-year old Type I plus vials showed an improvement factor of up to 350 times when compared with standard Type I vials.

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