Santosh Kesarpu: Leading innovation in complex generic development

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Santosh Kesarpu has established expertise in complex generic formulation, applying rigorous science to develop medicines that address unmet therapeutic needs. 

When national shortages and growing demand for pediatric- and geriatric-friendly formulations exposed vulnerabilities in the supply of critical central nervous system therapies, the problem was not merely logistical: it was technical. Recreating the performance of innovator drugs in generics—especially extended- and modified-release systems, multiparticulate technologies and formulations with narrow therapeutic windows—requires advanced formulation engineering and cross-functional collaboration to achieve consistent performance. 

In this context, Santosh Kesarpu has played a key technical role, combining advanced formulation science, regulatory strategy and manufacturing scale-up to restore supply, preserve product quality and shape a company strategy that prioritizes first-to-file and high-barrier generics.

Kesarpu’s work is situated at the interface of pharmaceutical science and regulatory practice. His remit spans the full formulation lifecycle for oral solids and liquids—immediate- and extended-release tablets and capsules, multiparticulate systems, chewable and orally disintegrating tablets, suspensions and solutions, and topical and ophthalmic preparations. 

Technically grounded in Quality by Design (QbD), he routinely applies Quality Target Product Profile (QTPP) frameworks, Design of Experiments (DOE) and multivariate statistical approaches through tools such as Stat-Ease and Minitab to define robust design spaces and reduce developmental iteration. These practices, encouraged by regulatory authorities, serve to minimize commercial batch failures and de-risk regulatory submissions.

Among Kesarpu’s notable program achievements is the lead development and regulatory filing of complex ADHD generics employing Multi-Unit Particulate Systems (MUPS) and ion-exchange delivery platforms. One MUPS-based product he led achieved approval at first review—an outcome that helped mitigate market shortages and improve patient access. Another program delivered a chewable ADHD formulation tailored for pediatric and geriatric use, reflecting a patient-centric design philosophy that balances dosage form palatability, stability and bioavailability.

Kesarpu’s technical portfolio also includes establishing in-vitro–in-vivo correlations (IVIVC) for products with partial area-under-the-curve (AUC) requirements and for highly variable drugs. He employs both convolution/deconvolution and model-independent numerical approaches—Wagner-Nelson and Loo-Reigelman methods among them—to align dissolution performance with human pharmacokinetic profiles. This capability enables more predictive bioequivalence strategies and can reduce the need for extensive in-vivo studies when supported by validated IVIVC models.

Beyond laboratory innovation, his responsibilities encompass scale-up and validation of R&D formulas to commercial manufacturing—managing complex unit operations including Wurster coating, high-shear granulation, extrusion and spheronization, pan coating, encapsulation and compression.

 He authors Product Development Reports, process validation protocols and registration batch documentation, drafts controlled regulatory correspondence, and responds to CMC-related deficiency response letters, information requests and complete response letters. Serving as a subject matter expert during pre-approval inspections, Kesarpu has contributed to audit outcomes that supported positive regulatory outcomes during manufacturing and quality inspections; in one recent inspection his leadership coincided with a single minor observation that was promptly resolved.

Kesarpu’s technical decisions have also influenced strategic direction. His success in delivering first-to-file ANDA candidates in high-value therapeutic areas prompted the organization to focus on paragraph IV, 505(b)(2), and other complex generic programs. His promotion from formulation scientist through senior scientist to associate director reflects both project-level impact and leadership across cross-functional development teams.

“Formulation is not an afterthought; it is the determinative engineering layer that makes a molecule usable,” Kesarpu said. “Our responsibility is to translate pharmacology into reliable, patient-ready medicines while meeting the rigorous expectations of regulators and manufacturers.”

A peer in formulation development observed, “Santosh merges rigorous statistical design with deep hands-on process knowledge. He is the kind of technical leader who can translate lab success into reproducible commercial batches and credible regulatory submissions—work that materially improves product availability.”

His contributions are based on organizational deliverables like approvals, validated scale-up, and audit stability, but they have big effects on the bigger picture. His work on chewable and orally disintegrating forms that focus on the patient makes it easier for vulnerable groups to stick to their treatment plans. 

His IVIVC approaches and QbD practices make it easier for generic drugs to be made again and again, and his regulatory stewardship speeds up patients’ access to cheaper treatment options. Together, these results support public health goals by making sure that supplies are always available, protecting product quality, and making it easier for people to get important medicines.

As the industry pivots toward more complex dosage forms and sustainable manufacturing paradigms, Kesarpu’s technical leadership exemplifies how integrated formulation science, statistical rigor and regulatory strategy can be marshaled to solve pressing supply and therapeutic challenges. His continuing focus on scalable, quality-driven development positions him as a continuing contributor to the advancement of complex generic pharmaceutical development—an engineer of formulations whose work materially affects patients, regulators and markets alike.