Product blinding
Product blinding
Maintaining blinding is critical throughout the CTS process. KLIFO’s blinding services start with from masking of products, ensuring that neither patients nor investigators can identify the treatment being administered. Blinding does not end there. KLIFO has established robust processes to ensure the blinding is maintained throughout our label design, packaging and labelling and distribution processes. Even day-day activities like communication with clients and clinical trial sites can potentially unblind a clinical trial, so maintenance of the blind is central to all activities at KLIFO.
Why product blinding matters for sponsors
Failure to protect the blind can compromise data integrity, delay study timelines, and in extreme cases, jeopardize an entire trial. Unblinding can happen at all stages the CTS process, so selection of an experienced partner is critical to its prevention.
Regulatory and ethical considerations
Global regulatory authorities require sponsors to justify and document their blinding methods. Compliance involves more than masking appearance—it also demands traceability, quality assurance, and patient safety safeguards.
Our services align with:
- International regulatory guidance for clinical trials.
- Ethical frameworks ensuring patient consent and protection.
KLIFO’s documentation processes support audits and inspections of blinding methods.
We work with clients to ensure that blinding strategies are not only effective but also defensible during regulatory review.
Challenges and innovative approaches
Not all investigational products can be blinded easily. Differences in viscosity, color, or packaging materials often require creative solutions. KLIFO helps sponsors navigate these challenges by:
- Identifying risks of unblinding early in study planning.
- Suggesting alternative designs where appropriate.
- Partnering with external specialists when placebo development or analytical support is needed.
By combining robust internal processes with a strong partner network, we deliver reliable solutions even for complex product types.
Development phases we support
Blinding is relevant across all trial phases but becomes especially critical from Phase II onwards when placebo- and comparator-controlled trials become more common. KLIFO supports sponsors throughout development with deliverables including:
- Product blinding strategies adapted to investigational and comparator products.
- Randomization and coding systems that ensure unbiased distribution of study medication.
- Labeling and packaging services designed to preserve blinding integrity.
- Distribution oversight to avoid unblinding through shipping or customs documentation.
Guidance through every phase
As part of a wider group, KLIFO’s CTS team can call upon expertise from our Advisory teams (example: CMC experts, Regulatory Affairs) to support the development and delivery of blinding strategies for the most complex of projects.
While KLIFO cannot perform all services required to blind products in-house, we can advise on blinding strategy and either subcontract work to approved partners or advise clients on where work can be done.
KLIFO can perform services such as over-labelling of vials and prefilled syringes to mask their contents. This works if vials/syringes are the same size, and if parts of the vial/syringe still visible after over-labelling are identical. If this is not the case, KLIFO works with a supplier of masking devices that can mask the entire dose unit, meaning that differences in size and appearance are no longer an issue. Developing custom masking devices can have long lead times, so should be planned in advance.
The most common approach we see when products are physically different is to employ a double-dummy design (e.g. Active Product A + Placebo Product B vs Placebo Product A + Active Product B). If placebo products cannot be produced by KLIFO, we have approved suppliers that may be able to produce these.
Blinding of products for clinical trials can be challenging, and our advice is that if this is required, talk to us early!
This ranges from activities such as creating blinded lot numbers for labels applied to kits used in double blind trials, through to ensuring that inventory reports and other information shared with ‘blinded’ personnel do not risk unblinding the trial. If we are performing packaging for a double-blind clinical trial, we perform blindness checks as part of our in process testing to ensure kits are identical across treatment groups. Checking of incoming packaging components (especially printed components) includes verifying items are consistent across each batch. Distribution documents (e.g. customs invoices, import licenses, pack lists) that may be viewed by blinded personnel at the Sponsor company, CRO or clinical site are also produced in a blinded format.
Protecting the blind is not just about processes, but also includes training of our customer-facing staff. This also needs to include staff at our partner companies – for example, our third party depots. We have heard from the industry about episodes where clinical sites have lost packing lists from a delivery, and have asked their local depot if they can provide a list of what they should have received. The depot helpfully provided a full list of everything shipped…in an unblinded document.
can help with comparator development, and can produce on any additional documentation that needs to be submitted to support product blinding. We can also advise on requirements such as analytical support for blinded products to demonstrate that the blinding process did not have a detrimental effect on dissolution times or stability of the blinded product.
Ensuring trial success through blinding
Maintaining the blind is one of the most important aspects of clinical trial supply. At KLIFO, we help sponsors safeguard their data, protect patients, and meet regulatory expectations through robust and innovative product blinding solutions.
By partnering with KLIFO, you gain not only technical expertise but also a trusted advisor who can guide you through the complexities of blinding design, implementation, and compliance—ensuring your trial remains on track and scientifically sound.
