Click on each stage of our industry leading route scouting and selection workflow to find out more.


Start with the ‘why’: Before starting your route selection process, it is important to ask the following questions:

  • Why are you looking for a new route?
  • What stages of development are you in?
  • Are you looking for an enabling route or a long-term commercial synthesis?
  • What are your main drivers for selecting a new route?
  • How do you want to manufacture your API?
  • What are your timelines?

By fully understanding your objectives, we will be able to design and develop the most appropriate route for your API.

Idea Generation

It is key to generate a wide range of ideas when designing a new synthesis. To ensure that all ideas have been explored, we follow three streams:

  1. Utilise the chemistry experience of our team, with a variety of technical backgrounds, to generate a multitude of ideas on paper
  2. Create additional ideas through the exploitation of industry leading retrosynthesis software tools
  3. Work closely with the customer to gain a full understanding of their ideas and incorporate these into our thinking


Chance of Technical Success (COTS) Assessment

The most critical part of any new route selection is predicting the Chance of Technical Success (COTS). Our internal tool drives a rigorous, objective assessment of all routes and predicts a score for COTS of each route. The benefits are:

  • Structured approach to assessing every step of each route
  • Taking away individual scientist biases
  • Identifying which steps will have the greatest risks and require the most attention
  • Overall route assessment displayed in a simple visual manner, allowing clear articulation of risk to the customer

Diagram 1 shows an example of a COTS measurement output. For this 5-step synthesis, we had very high confidence in 4 of the steps working well, driven by literature precedent and internal knowledge. It was clear that step 4 carried more risk; this understanding helped us to drive an efficient strategy to rapidly prove the viability of this route.

Environmental Impact Assessment

Until a process has been developed, it is not possible to give an accurate figure for environmental impact. However, we can predict the PMI factor of each route by utilising a tool developed by the ACS Green Chemistry Round Table. Some of the factors that the tool assesses include:

  • Reaction times
  • Molecule Complexity
  • Any reagents which could cause concern, such as heavy metal catalysts

The tool has been shown to give a reasonable correlation between predictive and actual values. As well as a predicted PMI, we also highlight any specific reagents or intermediates which may not be ideal from an environmental or safety perspective.

Route Costing Assessment

At the on-paper route ideation stage, it is not possible to ascertain an exact cost for the synthesis of a molecule. As such, we developed a simple costing tool that allows us to build relative and indicative costs for each route. We do this by considering:

  • Route length
  • Reagents and starting materials cost
  • Predicted yields
  • Preferred manufacturing strategy

If we understand more about where you may want to manufacture material and commercial volumes, we can adjust some parameters to give a closer estimate.

Try our free route costing calculator to estimate the cost of your materials and operations, along with the total cost of each step and the entire route.


Planning – Idea Prioritisation

We prioritise the generated ideas based on the phase of development that the project is in, and any specific requirements that the customer highlights.

For Early Development projects, we look at:

  • Speed: Rate at which we can deliver a phase-appropriate synthesis
  • COTS: Likelihood of paper idea working effectively in practice
  • Effort required: Cost and time to reduce ideas to practice

For Late Development projects, we look at:

  • Value: Predicted COG
  • COTS: Likelihood of paper idea working effectively in practice
  • Effort required: Cost and time to reduce ideas to practice

Planning – Resource Requirements

We develop a plan based on the required resources, focusing on:

  • Our customer’s specific requirements to provide the flexibility they require
  • De-risking the project as rapidly as possible
  • Getting to key decision points on each route as quickly as possible
  • Regulary reassessing options as we learn more about the chemistry


Once an agreed plan has been developed, the next step is to practically demonstrate the chemistry. We deliver this by leveraging our expert team, state-of-the-art facilities, and Ways of Working.

Expert team and state-of-the-art facilities:

  • Decades of experience in delivery of complex drug development projects across the CMC landscape
  • Supported by highly-qualified analytical experts and by dedicated analytical suite, including HPLC-MS, UPLC-MS, GC (MS & FID) and 400 MHz NMR
  • Dedicated technical project leader responsible for project delivery
  • 7 state-of-the-art laboratories co-located in Cardiff, UK dedicated to the non-clinical development of small molecule therapeutics


  • Progress and work tracked and monitored in a way and cadence that suits you
  • Regular feedback to ensure that your voice is heard and expectations are met
  • Detailed report upon project completion

Why Choose CatSci For Your Route Scouting & Selection?

High Quality Idea Generation

Our CMC experts employ their diverse technical backgrounds and end-in-mind approach to generate a wide range of high-quality ideas tailored to your API’s development phase, timelines and unique requirements in terms of safety, cost, regulatory compliance, sustainability and IP.

Unbiased & Structured Route Assessment

We have developed a suite of industry leading tools that objectively assess any synthetic route across several areas, including Cost of Goods, Chance of Technical Success, environmental impact and resources required. This structured and unbiased approach ensures that you select the right route for your API.

Rapid Execution

After working closely with you to prioritise the generated ideas and create a plan based on your specific requirements, we practically demonstrate the chemistry, establish proof of principle and perform a demo batch. This is done within our state-of-the-art laboratories supported by a dedicated team of chemistry, analytical and solid-state experts.

Communication & Transparency

A dedicated technical project leader responsible for project delivery will provide you with updates in the format and cadence that suits you. We actively seek regular feedback from you to ensure that your voice is heard and expectations are met. Upon project completion we will deliver a detailed tech transfer package and can oversee its implementation with your manufacturing partner.

Customer Success Story


Check out our whitepaper to find out how we help our customers to improve the scalability, robustness, safety, efficiency, commercial viability and sustainability of their processes.


Free Route Costing Calculator

Digital Tool

Work out the cost of your synthetic route with our free, easy-to-use cost calculator