Principal Scientist, Long-Acting Injectable Sterile Product Development

Merck; Rahway (NJ); On-site; USD 173,000 - 273,000; Full time

Job summary

Merck is seeking a Principal Scientist to lead LAI formulation strategy across a portfolio of long-acting injectable drug products, including depot and sustained-release systems. The role involves scientific leadership across multidisciplinary teams, shaping development strategy and lifecycle management.

The candidate will define critical quality attributes, oversee studies on release kinetics and stability, and ensure manufacturability and clinical applicability while mentoring junior

Qualifications

• Deep expertise in parenteral drug product development and LAI formulations.
• Proven experience with QbD and DOE in formulation/process development.
• Experience supporting scale-up, validation and tech transfer for sterile injectables.

Responsibilities

• Lead LAI formulation and delivery strategy across programs.
• Define CQAs and CPPs for LAI projects and guide cross-functional teams.
• Support clinical and commercial process scale-up and tech transfer to GMP facilities.
• Mentor junior scientists and drive data-driven decision making.

Skills

Parenteral drug product development

LAI formulations

Cross-functional leadership

QbD principles

DOE approaches

Education

Ph.D. with 7+ years

M.S. with 10+ years

B.S. with 14+ years

Tools

GMP manufacturing

In situ forming systems

Job description

The Sterile Product Development group is responsible for the development of parenteral dosage forms, including long-acting injectables (LAIs), across small molecules, peptides, and biologics from preclinical development through commercialization. Our teams enable robust and scalable drug product and delivery solutions through deep scientific understanding of formulation, drug–excipient interactions, delivery system performance, and manufacturing processes, ensuring product quality, safety, efficacy, and patient-centric design.

This role is a Principal Scientist–level technical leadership position with a primary focus on long-acting injectable drug products, including depot formulations, extended-release systems, and injectable sustained-delivery technologies. The successful candidate will serve as a scientific leader across multidisciplinary teams, shaping LAI formulation and development strategy across the portfolio.

Primary Duties

• Serve as a principal-level LAI formulation scientist, providing scientific leadership for the design, development, and lifecycle management of long-acting injectable drug products, including depot, sustained-release, and controlled-delivery parenteral dosage forms
• Lead LAI formulation and delivery strategy development, including selection and optimization of release mechanisms (e.g., polymer-based depots, suspensions, microspheres, in situ forming systems), excipient systems, and delivery approaches to meet target product profiles
• Provide strategic technical leadership on cross-functional program teams, ensuring alignment of formulation, drug substance properties, delivery system performance,
• container/closure systems, manufacturability, and clinical use considerations throughout development
• Design and interpret studies to understand and control release kinetics, stability, and performance, including:
• Drug–excipient and drug–polymer interactions
• In vitro and in vivo performance relationships
• Physical stability, aggregation, and particle size control
• Syringeability, injectability, and device compatibility
• Support early- and late-stage development programs, including:
• Selection of scalable manufacturing processes for LAIs
• Definition of formulation and process design space
• Support for clinical and commercial process scale-up and validation
• Technology transfer to GMP manufacturing facilities
• Partner closely with Clinical, Non-Clinical, Quality, Regulatory, Manufacturing, and Engineering teams to:
• Define critical quality attributes (CQAs) and critical process parameters (CPPs) relevant to LAI performance
• Support clinical strategy through formulation design and risk mitigation
• Contribute to CMC regulatory submissions and health authority interactions
• Provide scientific oversight and mentoring to junior scientists, fostering capability development in LAI formulation science, experimental design, and data-driven decision making
• Maintain awareness of emerging LAI technologies and delivery platforms, contributing to internal capability assessments, external collaborations, and innovation initiatives aligned with portfolio and organizational strategy

Minimum Education Requirements

• Ph.D. with 7+ years industry experience, or
• M.S. with 10+ years, or
• B.S. with 14+ years in Pharmaceutics, Pharmaceutical Sciences, Chemical Engineering, Biochemical Engineering, Chemistry, Materials Science, or a related discipline

Required Experience And Skills

• Deep expertise in parenteral drug product development, with demonstrated experience in long-acting injectable or sustained-release formulations
• Strong scientific understanding of:
• Controlled-release mechanisms and LAI delivery systems
• Drug–polymer and drug–excipient interactions
• Formulation stability and performance characterization
• Experience applying Quality by Design (QbD) principles and DOE approaches to formulation and process development
• Experience supporting process scale-up, validation, and technology transfer for sterile injectable products
• Working knowledge of CMC regulatory expectations for parenteral and extended-release products, including development-stage and commercial submissions
• Demonstrated ability to lead cross-functional teams, influence strategy, and communicate complex scientific concepts clearly
• Proven mentoring and scientific leadership skills at the senior/principal level

Preferred Experience And Skills

• Experience with LAI-specific platforms, such as polymer depots, microspheres, nanosuspensions, or in situ forming systems
• Experience with device–drug product integration, including prefilled syringes or delivery systems relevant to LAIs
• Understanding of clinical and patient-centric considerations influencing LAI design (e.g., dosing interval, injection volume, administration route)
• Experience supporting global regulatory filings and health authority interactions
• Track record of contributing to publications, patents, or external scientific collaborations in drug delivery or formulation science

Required Skills

Adaptability, Adaptability, Cell Culture Process Development, Cell Line Development, Combination Products, Data Analysis, Drug Delivery, Drug Development, Drug Formulations, Finite Element Analysis (FEA), Functional Management, Innovative Thinking, Leadership Mentoring, Pharmaceutical Process Development, Pharmaceutical Products, Pharmaceutical Research, Pharmaceutical Sciences, Pharmaceutics, Process Development (PD), Process Scale Up, Product Development, Product Development Lifecycle, Product Formulation, Professional Collaboration, Professional Networking {+ 8 more}

US And Puerto Rico Residents Only

Our company is committed to inclusion, ensuring that candidates can engage in a hiring process that exhibits their true capabilities. Please click here if you need an accommodation during the application or hiring process.

Requirements

As an Equal Employment Opportunity Employer, we provide equal opportunities to all employees and applicants for employment and prohibit discrimination on the basis of race, color, age, religion, sex, sexual orientation, gender identity, national origin, protected veteran status, disability status, or other applicable legally protected characteristics. As a federal contractor, we comply with all affirmative action requirements for protected veterans and individuals with disabilities. For more information about personal rights under the U.S. Equal Opportunity Employment laws, visit: EEOC Know Your Rights EEOC GINA Supplement We are proud to be a company that embraces the value of bringing together, talented, and committed people with diverse experiences, perspectives, skills and backgrounds. The fastest way to breakthrough innovation is when people with diverse ideas, broad experiences, backgrounds, and skills come together in an inclusive environment. We encourage our colleagues to respectfully challenge one another’s thinking and approach problems collectively.

Salary

The salary range for this role is $173,200.00 - $272,600.00.

This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. An employee’s position within the salary range will be based on several factors including, but not limited to relevant education, qualifications, certifications, experience, skills, geographic location, government requirements, and business or organizational needs.

Benefits

We offer a comprehensive package of benefits. Available benefits include medical, dental, vision healthcare and other insurance benefits (for employee and family), retirement benefits, including 401(k), paid holidays, vacation, and compassionate and sick days. More information about benefits is available at https://jobs.merck.com/us/en/compensation-and-benefits.

San Francisco Residents Only

We will consider qualified applicants with arrest and conviction records for employment in compliance with the San Francisco Fair Chance Ordinance

Los Angeles Residents Only

We will consider for employment all qualified applicants, including those with criminal histories, in a manner consistent with the requirements of applicable state and local laws, including the City of Los Angeles’ Fair Chance Initiative for Hiring Ordinance

Employee Status

Regular

Relocation

Domestic

VISA Sponsorship

Yes

Travel Requirements

10%

Flexible Work Arrangements

Not Applicable

Shift

Not Indicated

Valid Driving License

No

Hazardous Material(s)

n/a

Job Posting End Date

09/19/2026