Meet Josh de Los Santos – Senior Manager, Drug Product Manufacturing at Argonaut
From N-of-1 fills, to thousands of vials, Josh’s team delivers sterile fills with tight PM cadence and low rejects—learn how Argonaut safeguards your timeline.
What’s a day like in managing drug product manufacturing?
“There’s no typical day,” Josh laughs. He leads the Drug Product Manufacturing team responsible for tech transfer, formulation, sterile filling, visual inspection, shipping, and the countless details that make a batch fill go right, the first time. Mornings often start with facility stand-ups or installer check-ins, followed by client meetings to finalize batch records, components, filtration, and fill execution. Internally, he keeps a tight cadence with the team: “We plan ahead, then pivot fast when priorities change.” This keeps the fill lines in a high state of readiness, able to produce multiple batches a week while hitting clients’ timelines.
How does your work support Argonaut’s mission?
“We’re the last to work with the drug before it’s in a vial—and the last ones to confirm the filled vials have met regulatory and client requirements,” Josh says. His team prides itself on producing batches with reject rates consistently below 1%. Adhering to controlled procedures helps ensure this outcome.
N-of-1 vs. larger fills. What’s different for a single-fill run?
Philosophically, we treat every fill the same,” he explains. “N-of-1’s feel special because they’re for a single patient—often in an underserved population—so the impact for a patient is tangible. With larger fills, the satisfaction comes from delivering a product that will help communities. Either way, a happy client email that says ‘thank you’ means a lot to my team.”
Josh de Los Santos’ team prides itself on producing batches with low reject rates consistently below 1%
What challenges do you navigate?
- Time pressure: “Some days you wish for a few more hours to make the project even smoother—but we keep multiple clients happy without cutting corners.”
- Components & supply chain: During the COVID-era, sterilized components had long lead times and it was challenging to maintain timelines. “Relationships with vendors—and a few timely favors—kept us on schedule.”
What makes your team effective?
“We are a tight unit with shared ownership,” Josh says. “You’ll find supervisors on the line when needed—that’s not typical at our level, but it matters and delivers faster troubleshooting.” The team mirrors that dedication: “I never have to ask for overtime; there are always volunteers.” Personalities differ, but they mesh: “People know what needs to get done and execute without micromanaging.” He credits this to the experience of the team, their cross-training, and the wide variety of products they have filled.
A moment that shows the team’s grit
Early on, a robotic handler misbehaved during a fill. “Once product is thawed and on the line, you can’t stop,” he recalls. The team stayed through the night to finish. “They could have gone home—but they stayed. That’s the culture.” These actions saved the product and kept the client on their timeline.
“People know what needs to get done and execute without micromanaging.”
Leadership style
“Lead by example,” he says. “If the trash needs to go out, I take it out. If someone’s needed in the fill room, I’m there. Show the dedication you want to see.”
Life outside work
“I’m a serial tinkerer,” Josh smiles. The hobbies rotate—motorcycles, plants, and lately fermentation. “It’s all experiments—like solving small puzzles,” which maps back to manufacturing: “Each client brings a new challenge to engineer around.”
Advice for someone pursuing a career in biomanufacturing
“Study the science, know the regulations, and keep your network warm” he advises. “Stay current—things change fast. Biotech is small and relationships matter.”
Argonaut is your trusted CMO partner for aseptic fill-finish, IVD and life science applications, and drug-device combination products (DDCP). Our highly experienced team delivers flexible, responsive manufacturing solutions with complete product configuration, formulation, kitting, QC/QA, and supply-chain management. With extensive regulatory expertise ensuring high standards, and a dedicated program manager driving transparency and clear communication, Argonaut keeps your programs on track from start to finish.
Discover how Josh de Los Santos and the Argonaut staff can elevate your manufacturing processes—reach out to us today to learn more!
