Find a contract manufacturer (CMO) or custom synthesis (CDMO) focused on the the production of large scale (multi-gram) peptide APIs using technologies like solid-phase or liquid-phase synthesis. Some CMOs also offer capabilities to develop recombinant peptides and protein products using microbial expression systems. Find proven strategic contract manufacturing partners who appreciate the differentiation that solid-phase synthesis and solution-phase synthesis. Solid phase synthesis offers the benefits of shorter process development and manufacturing time with greater cost efficiency at small to medium-scale production, but also remains competitive for larger-scale processes and for producing longer sequences and more complex peptides with elaborate side chains. Solution-phase synthesis on the other hand may be advantageous as product quantities increase. The key is to optimize process development and achieve highly efficient conversion at every amino acid coupling to achieve high-purity custom peptide synthesis and minimize the demands on downstream processing. Ensure that your CMO/CDMO offers cost analysis, project review, R & D process optimization and detailed qualification reports all stages of large scale peptide production. Utilize state of the art proprietary manufacturing technologies, with a full array of services to take your drug substance project from pre-clinical to commercial scale. Ensure that your contract manufacturer (CMO) or custom synthesis (CDMO) organization applies the Quality by Design (QbD) in the production steps for the manufacture of your peptide API. This compels them to selectively characterize the steps requiring a design space. Have the CMO/CDMO focus attention on critical process steps such as cleavage-deprotection, oxidation, purification, isolation & lyophilization and make sure the corresponding critical parameters are thoroughly challenged. Solid Phase Peptide Synthesis assembly requires further attention for design space as it is necessary to employ PAT on line and defining Quality Attributes of a Process. Although the Critical Quality Attributes of the peptide APIs have the most prominent place when designing a process, it is not sufficient to design a process only with the CQAs in mind. The scope of the quality concept has to be expanded to encompass all quality attributes of a process, which are: Critical Quality Attributes of the product; Yield; Throughput (e.g. kg/day); Costs; Robustness (e.g. scalability, reproducibility, lack of deviations, out of specifications, out of trends, reprocesses, reworks etc).