As topical drug products become more complex, reformulation is becoming a more common and more important part of product development. Sponsors may need to replace an excipient, resolve texture or viscosity problems, address poor release, improve stability, respond to regulatory questions, improve patient usability, or rescue a formulation that cannot be scaled.
For CPL, these challenges align directly with the company’s core expertise. CPL does not treat topical and semi-solid products as a small part of a broader dosage form portfolio. Semi-solids and liquids are the foundation of the business. That focus gives sponsors access to a team, facility, equipment base, and development philosophy built specifically around the realities of topical product performance.
Decades of Focus on Semi-Solids and Liquids
CPL’s strength begins with focus. The company has spent more than 30 years working with semi-solid and liquid dosage forms, including creams, ointments, gels, lotions, and related topical products. That experience matters because topical drug development involves challenges that are very different from solid oral dosage forms.
In semi-solids and liquids, excipient interactions are more dynamic. Process conditions can dramatically affect product structure. Rheology, viscosity, globule size, drug release, skin penetration, and patient experience are interrelated, and all need to be understood together. A formulation that looks correct on paper may fail because it is too stiff, too unstable, too difficult to scale, or unable to release the drug appropriately.
CPL has seen many of these challenges through projects brought to the team over the years. That experience allows the company to recognize warning signs earlier, investigate issues more efficiently, and apply lessons learned from past reformulation and scale-up challenges.
A Practical Example of Reformulation Rescue
One example shared by CPL’s subject matter experts involved a sponsor with an ointment developed elsewhere. On paper, the formulation appeared promising. In practice, the product was too hard and could not be squeezed from the tube. The sponsor discovered the problem as they were preparing to send the product to a clinical site, creating an urgent need for a solution.
CPL’s team quickly gathered the technical details, evaluated the molecule, assessed the formulation, and identified a path forward. Within a week, the team reformulated the product by adjusting the solvent system and changing the matrix. The result was a softer ointment that could be dispensed more easily while maintaining stability.
The work did not stop at the lab bench. CPL then manufactured 10 kg batches, followed by 100 kg batches, and eventually scaled the product further for clinical supply. The sponsor was able to meet its clinical timeline because CPL addressed not only the immediate usability problem, but also the scale-up pathway needed to move the program forward.
This example reflects an important point about topical reformulation. The issue is not always whether a formulation contains the right API or has theoretical potential. Sometimes the problem is whether the product can actually be used, manufactured, reproduced, and advanced within the sponsor’s timeline.
Reformulation With Regulatory Awareness
In that same rescue project, CPL also had to consider global regulatory constraints. The team needed to select excipients that could solve the technical problem without creating unnecessary toxicology or agency concerns.
Even commonly used excipients have acceptable use levels. If those levels are exceeded, sponsors may need to conduct additional toxicology work or provide further justification. For programs already moving toward clinical use, that can create delays.
CPL’s approach is to reformulate with regulatory awareness from the beginning. The team considers whether excipients are appropriate for the dosage form, route, and intended use, and whether their levels are supported by existing regulatory precedent. This helps sponsors solve formulation problems without introducing avoidable complications.
The Importance of QTPP, CMAs, and CPPs
CPL’s development approach is built around understanding the quality target product profile, or QTPP. Before a product can be successfully formulated or reformulated, the team needs to understand what the final drug product must achieve. That includes , usability, dosage form, stability, performance, manufacturing expectations, regulatory requirements, and patient needs.
From there, the team evaluates critical material attributes(CMAs), including the raw materials and excipients that may influence product quality. In topical products, CMAs can have a major impact on , emulsion structure, drug release, viscosity,, stability, and reproducibility. Even when a raw material meets a supplier’s specification, the range within that specification may affect how the product behaves.
CPL also evaluates critical process parameters (CPPs). Equipment selection and processing parameters like mixing time, temperature, homogenization, cooling, vacuum, can all influence the final product. Understanding these CPPs helps ensure that the process can be controlled, scaled up, and reproduced as the product moves from lab scale to clinical and commercial manufacturing.
This connection between QTPP, CMAs, and CPPs allows CPL to develop products that are not only technically sound, but also practical to scale.
Integrated Formulation, Skin Lab, and Scale-Up Support
One of CPL’s strongest advantages is the integration of formulation development, analytical support, skin lab capabilities, scale-up, and manufacturing under one roof. This matters because topical development cannot be separated neatly into isolated stages.
A scientist working on a formulation can connect directly with the manufacturing floor to understand how a process will behave on a larger scale. If there is a question about equipment, mixing, temperature control, or batch reproducibility, the team can evaluate those issues early rather than waiting until transfer or scale-up.
CPL also has skin lab capabilities, including IVRT and IVPT support, which allow the team to evaluate drug release and skin permeation as part of the development strategy. These tools are especially important when reformulation involves excipient changes, vehicle changes, or attempts to match the performance of a previously studied or approved product.
The ability to connect formulation changes with rheology, release testing, permeation testing, and scale-up considerations gives sponsors a more complete picture of product performance that is important from a clinical efficacy perspective.
Equipment Designed for Reproducibility
Topical and semi-solid products require strong process control. CPL’s scale-up and manufacturing equipment includes capabilities such as mixing, homogenization, positive or negative pressure, and tight temperature control. These features help support reproducibility as products move from smaller batches to larger clinical or commercial scales.
That reproducibility is essential. A product that performs once is not enough. Sponsors need a process that can produce consistent batches across scale, time, and material variability. CPL’s equipment and process expertise help reduce the risk that a product will behave differently as volume increases.
Why Reformulation Demand Is Likely to Increase
CPL’s team expects reformulation needs to continue increasing over the next several years. Regulatory agencies are asking more detailed technical questions about excipient levels, excipient safety, chemical behavior, extractables and leachables, impurity risks, and product equivalence. At the same time, analytical instrumentation has become more sensitive, which means issues that may have gone undetected in the past are now more likely to be identified and questioned.
Nitrosamines and other impurity concerns have also affected how sponsors and suppliers think about excipients. In some cases, excipient manufacturers may move away from pharmaceutical-grade offerings or change how certain materials are supplied. That can force sponsors to identify alternate suppliers or reformulate with equivalent excipients.
For topical products, these substitutions are rarely simple. Two excipients may look similar on paper but behave differently in a formulation, especially when they influence , microstructure, rheology, viscosity or drug release. Changing a thickener or polymer-based excipient can alter entirely Q3 properties, IVRT results, product feel, stability, and process behavior.
As CPL’s team summarized, more technical questions often lead to more reformulation work. Sponsors will need partners that can respond with both scientific depth and practical manufacturing experience.
A Partner for Today’s Reformulation Challenges and Tomorrow’s Expectations
CPL is positioned for this future because its capabilities are already aligned with the direction topical development is moving. Sponsors need more than a manufacturer. They need a partner that understands formulation science, excipient behavior, skin performance, rheology, regulatory expectations, and scale-up.
They also need a team that can move quickly when timelines are tight. Underperforming products often arrive with urgency. A clinical batch may be delayed. A stability concern may threaten a milestone. A regulatory question may require a thoughtful response. A supplier change may force rapid reformulation.
CPL’s value is its ability to bring these pieces together. With decades of focus on semi-solids and liquids, integrated development and manufacturing, IVRT and IVPT capabilities, rheological expertise, and scale-up equipment designed for reproducibility, CPL helps sponsors turn topical reformulation from a setback into a disciplined path forward.
For sponsors developing or rescuing topical drug products, the best time to involve CPL is early. But even when challenges appear later, CPL offers the focused experience needed to identify the issue, reformulate strategically, and keep the program moving toward the next milestone.