A Thermal Stability Study of Phosphoramidites Employed in Oligonucleotide Synthesis
In the dynamic world of drug design, thermal stability plays a crucial role, often determining the success of manufacturing innovative treatments. As researchers push the boundaries of medicine, the need for robust and effective RNA- and DNA-based drugs has never been greater. The standard method of DNA synthesis utilizes phosphoramidite chemistry in solid phase oligonucleotide synthesis and in the latest liquid phase oligonucleotide synthetic approaches. However, as with all chemistry, it is important to understand the reaction hazards and safety potential of the starting materials and intermediates. In this blog, we will explore why the thermal stability aspect of phosphoramidite chemistry is vital in oligonucleotide drug development and manufacturing.
The Importance of a Safe Thermal Profile in Drug Development and Manufacturing
Thermal stability refers to a compound’s ability to maintain its structural integrity and functionality when exposed to heat. For RNA and DNA oligonucleotides, this means ensuring that these molecules do not degrade or lose their efficacy under various temperature conditions. Double stranded oligonucleotides denature or melt at higher temperatures. In addition, during oligonucleotide manufacturing, it is important to understand the thermal stability and exothermic, energetic release of the chemical components. This understanding is crucial to ensuring that oligonucleotide drugs are produced in a safe and scalable manner.
Oligonucleotide drug components with stable thermodynamic profiles ensure consistent performance and minimize the safety and hazard risks of storage and production, particularly as many oligonucleotide therapeutics are being scaled up to hundreds of kilograms or more. By understanding and optimizing the thermal stability of phosphoramidites, manufacturers can ensure the development of a safer and more reliable production process for commercial quantities of oligonucleotide therapeutics.
Study: Phosphoramidites in Oligonucleotide Synthesis
Nucleotide phosphoramidites are chemical building blocks used in the synthesis of oligonucleotides. They serve as the key components that are incorporated into the growing DNA or RNA strand during the synthesis process. These reagents are pivotal in constructing precise and functional nucleic acid sequences, making their stability critical for successful oligonucleotide synthesis.
Study Goals
The primary goal of the recent study was to investigate the thermal stability of various phosphoramidites and phosphodiamidites (“phosphoramidites”) used to synthesize nucleoside phosphoramidites or modify nucleotides and oligonucleotides. By understanding the temperature at which the phosphoramidites degrade, researchers aim to optimize their use in oligonucleotide synthesis, ensuring primarily safety and secondarily both the efficiency of the synthesis process and the quality and performance of the final product.
Research Methodology
The study employed a range of techniques to assess the thermal stability of phosphoramidites. These methods included differential scanning calorimetry and accelerating rate calorimetry (ARC). Both experiments were performed in a closed chamber under inert conditions to minimize outside interference. These methods helped to find the exotherm onset temperatures of the degradation and total energy released during the temperature ramped screening test. ARC was executed under pseudo-adiabatic conditions and provided additional information on gas generation during the test. These approaches provided a comprehensive view of how different phosphoramidites withstand heat.
Key Findings
The study revealed significant variations in thermal stability among different phosphoramidites. Some showed excellent stability at elevated temperatures, while others exhibited noticeable degradation by releasing a lot of energy, making them class 1 explosive species. These findings highlight the importance of selecting a safe phosphoramidite for the desired chemical reaction.
Tremendous Impact on Process Safety
The implications for process safety are substantial. Phosphoramidites with poor thermal stability increase risks during synthesis, including potential explosions or formation of hazardous byproducts and impurities. By identifying and addressing these safety and quality issues, manufacturers can implement improved chemical manufacturing processes which yield high-performing, safe, and stable oligonucleotide therapeutic intermediates.
Business Interruption Risks
Thermal instability can also pose risks to business operations, potentially leading to disruptions in production schedules and increased costs. Understanding and mitigating these risks through better phosphoramidite selection and handling procedures can help minimize business interruptions and maintain a steady supply of high-quality oligonucleotide drugs.
Keep Informed of the Latest Phosphoramidite Research with Entegris
The study of thermal stability in phosphoramidites underscores its critical role in oligonucleotide drug development and manufacturing. By ensuring that these key components remain stable under various conditions and lead to efficacious oligonucleotide therapeutics, researchers and manufacturers can enhance the performance, safety, and reliability of RNA- and DNA-based drugs.
Further research will explore new phosphoramidite compositions with improved thermal stability and will investigate alternative synthesis methods to enhance overall process stability and safety. Continued advancements in this area will contribute to the development of more effective and reliable nucleic acid-based therapies. We are currently working with customer collaborators to explore new phosphoramidite analogs that have safe exothermic profiles and achieve safe and robust manufacturing processes for oligonucleotide therapeutics and intermediates.
Will you consider collaborating with us on phosphoramidite thermal stability studies to help develop safe, consistent, and scalable manufacturing processes for your oligonucleotide therapeutics?
Learn more about this study and how Entegris is shaping the future of oligonucleotides in therapeutic development.
