Associate Principal Scientist, Long-Acting Injectable Sterile Product Development

Job DescriptionOverview: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 an Associate 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 DutiesServe as an 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 formsLead LAI formulation and delivery development for one or more programs, 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 profilesProvide 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 developmentDesign and interpret studies to understand and control release kinetics, stability, and performance, including:Drug–excipient and drug–polymer interactionsIn vitro and in vivo performance relationshipsPhysical stability, aggregation, and particle size controlSyringeability, injectability, and device compatibilitySupport early‑ and late‑stage development programs, including:Selection of scalable manufacturing processes for LAIsDefinition of formulation and process design spaceSupport for clinical and commercial process scale‑up and validationTechnology transfer to GMP manufacturing facilitiesPartner 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 performanceSupport clinical strategy through formulation design and risk mitigationContribute to CMC regulatory submissions and health authority interactionsProvide scientific oversight and mentoring to junior scientists on project teams, fostering capability development in LAI formulation science, experimental design, and data‑driven decision makingMaintain awareness of emerging LAI technologies and delivery platforms, contributing to internal capability assessments, external collaborations, and innovation initiatives aligned with portfolio and organizational strategyEnhance our Company’s professional image and competitive advantage through generation of patents, external presentations, publications, and professional organizations related to sterile product development and/or long-acting injectablesMinimum Education RequirementsPh.D. with 4+ years industry experience, orM.S. with 8+ years, orB.S. with 10+ yearsin Pharmaceutics, Pharmaceutical Sciences, Chemical Engineering, Biochemical Engineering, Chemistry, Materials Science, or a related disciplineRequired Experience and SkillsDeep expertise in parenteral drug product development, with demonstrated experience in long‑acting injectable or sustained‑release formulationsStrong scientific understanding of:Controlled‑release mechanisms and LAI delivery systemsDrug–polymer and drug–excipient interactionsFormulation stability and performance characterizationExperience applying Quality by Design (QbD) principles and DOE approaches to formulation and process developmentExperience supporting process scale‑up, validation, and technology transfer for sterile injectable productsWorking knowledge of CMC regulatory expectations for parenteral and extended‑release products, including development‑stage and commercial submissionsDemonstrated ability to lead cross‑functional teams, influence strategy, and communicate complex scientific concepts clearlyPreferred Experience and SkillsExperience with several LAI‑specific platforms, such as polymer depots, microspheres, nanosuspensions, or in situ forming systemsExperience with device–drug product integration, including prefilled syringes or delivery systems relevant to LAIsUnderstanding 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 interactionsTrack record of contributing to publications, patents, or external scientific collaborations in drug delivery or formulation scienceRequired Skills: Bioprocess Engineering, Bioprocess Engineering, Cell Line Development, Chemical Engineering, Downstream Process Development, Drug Delivery, Drug Delivery Technology, Drug Development, Drug Formulations, Early Phase Clinical Trials, Expression Vectors, Kinetics, Molecular Biology, Pharmaceutical Formulations, Pharmaceutical Process Development, Pharmaceutical Products, Pharmaceutical Research, Pharmaceutical Sciences, Pharmaceutical Technologies, Pharmaceutics, Physical Characterization, Product Development Lifecycle, Product Formulation, Regulatory Submissions, Stable Cell Lines {+ 1 more}Preferred Skills: Current Employees apply HERECurrent Contingent Workers apply HEREUS 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.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 RightsEEOC 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.Learn more about your rights, including under California, Colorado and other US State ActsThe salary range for this role is$142,400.00 - $224,100.00This 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.The successful candidate will be eligible for annual bonus and long-term incentive, if applicable.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 .You can apply for this role through (or via the Workday Jobs Hub if you are a current employee). The application deadline for this position is stated on this posting.San Francisco Residents Only: We will consider qualified applicants with arrest and conviction records for employment in compliance with the San Francisco Fair Chance OrdinanceLos 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 OrdinanceSearch Firm Representatives Please Read Carefully Merck & Co., Inc., Rahway, NJ, USA, also known as Merck Sharp & Dohme LLC, Rahway, NJ, USA, does not accept unsolicited assistance from search firms for employment opportunities. All CVs / resumes submitted by search firms to any employee at our company without a valid written search agreement in place for this position will be deemed the sole property of our company. No fee will be paid in the event a candidate is hired by our company as a result of an agency referral where no pre-existing agreement is in place. Where agency agreements are in place, introductions are position specific. Please, no phone calls or emails. Employee Status: RegularRelocation:DomesticVISA Sponsorship:YesTravel Requirements:10%Flexible Work Arrangements:Not ApplicableShift:Not IndicatedValid Driving License:NoHazardous Material(s):n/aJob Posting End Date:09/19/2026*A job posting is effective until 11:59:59PM on the day BEFORE the listed job posting end date. Please ensure you apply to a job posting no later than the day BEFORE the job posting end date. SummaryLocation: USA - New Jersey - RahwayType: Full time