Pharma Synthesis in India: Chasing Purity and Greener Routes

The problems being solved

Behind every generic drug and active pharmaceutical ingredient (API) lies a tangle of stubborn chemistry problems. Indian patent filings cluster around a few persistent themes: keeping impurities in check, squeezing more product out of each reaction, and making processes robust enough for factory floors.

Impurity control is a frontline concern. Inventors are chasing down specific troublemakers—maleic acid choline chloride ester, dimer impurities, unwanted regioisomers—that can derail a batch. The goal is often purity above 99.5% or even 99.9%, and that demands not just a good reaction but a meticulously engineered purification sequence.

Yield and efficiency are equally urgent. Teams are redesigning steps to shorten reaction times, sometimes with microwave assistance, or collapsing multi-step sequences into a single cyclization. The drive is to get more drug substance from the same starting materials while reducing solvent and energy bills.

Scalability threads through nearly every problem statement. A route that works in a flask must survive the leap to commercial scale without spawning new impurities or dropping yield. That means choosing reagents that are cheap and available, and designing workups that don’t rely on finicky filtrations.

Environmental and safety pressures are reshaping choices too. Patents describe water-based syntheses, solvent-free conditions, and swaps that avoid toxic reagents like diphenyl carbonate. The aim is to lower the process mass intensity and make the plant safer.

Finally, the solid form matters. Getting the right polymorph—say, Form C or Form-M—or a specific solvate is critical for bioavailability and shelf life. Innovators are engineering crystallizations that reliably deliver the desired crystal lattice, often by controlling anti-solvent addition or isolating a transient solvate.

How the field is solving it

The tool chest is expanding. One major lever is reagent and catalyst tuning. Phase transfer catalysts are being deployed to suppress regioisomer formation, while palladium catalysts and coupling agents like EDC.HCl with DMAP are chosen to steer selectivity and push yields higher.

Controlled addition is a quiet workhorse. By metering in a reactant slowly or running a stepwise sequence, chemists can starve side reactions that would otherwise generate dimers or esters. Temperature and pressure are dialled in to narrow the impurity profile.

Solvent engineering is getting greener and smarter. Toluene and chlorinated solvents still appear, but water is increasingly the medium of choice. Some processes go solvent-free, and others simplify workup by sticking to a single solvent system, skipping filtration steps that waste product.

Crystallization is being treated as a purification step in its own right. Recrystallization from a carefully chosen solvent pair, or isolation of an isopropyl alcohol solvate, can knock out impurities that survive the reaction. Polymorph control is baked into the cooling profile and seeding strategy.

Impurity mitigation is often built into the route. Hydrogenation of an impurity-laden intermediate, or the use of a phase transfer catalyst to avoid a regioisomeric pathway, turns a purification headache into a solved problem at the reaction stage.

Novel synthetic routes are emerging too. A mixed anhydride approach or a single-step cyclization can bypass problematic intermediates altogether, offering a cleaner, shorter path to the target molecule.

Where the market is heading

The global pharmaceutical market stood at roughly USD 1.7 trillion in 2025 and is growing at a mid-single-digit annual rate, according to Grand View Research. Synthesis is the engine room of that value, and India is a dominant player—a leading global supplier of generic medicines and APIs, as highlighted in the Department of Pharmaceuticals Annual Report 2025-26.

Government schemes like the Production Linked Incentive (PLI) and the Scheme for Promotion of Research and Innovation in Pharma MedTech (PRIP) are pouring momentum into domestic manufacturing and R&D. This policy push is reinforcing India’s role as the pharmacy of the world.

On the technology front, high-throughput experimentation and machine learning are accelerating synthesis optimisation from discovery to production, notes a recent Science review. Visible-light photocatalysis and engineered enzymes are adding new dimensions of selectivity and sustainability. PwC’s Future of Pharma report points to AI-driven drug R&D, synthetic biology, and computational chemistry collapsing timelines for new medicines. Meanwhile, Evonik’s pharma synthesis outlook underscores that sustainability and process efficiency are becoming core requirements, with waste reduction and greener pathways now table stakes.

The white space

Plenty of room remains for Indian innovators to lead. Integrating machine learning into reaction optimisation could slash the trial-and-error that still dominates process development. Continuous flow synthesis, barely visible in the current patent landscape, offers a leap in efficiency and safety for high-volume APIs.

Green chemistry is an open invitation. Water-based and solvent-free methods are still the exception, and there is a wide lane for processes that cut solvent use, replace toxic reagents, and lower energy footprints without raising cost.

Complex generics and niche APIs present a rich seam. Novel routes that bypass patent-protected intermediates or that access difficult polymorphs can create durable manufacturing advantages. Coupling these routes with robust crystallisation design can lock in purity and solid-form consistency.

Finally, the push toward self-reliance in key starting materials and intermediates—backed by PLI schemes—opens a space for homegrown, scalable synthesis of building blocks that are currently imported.

Explore the innovators

The inventors, patents, and companies working on these synthesis challenges in India can be explored on Deeptech Navigator. From impurity-busting catalysts to water-based routes and polymorph control, the detailed work of Indian researchers is waiting to be discovered.

In our data

Sources

• The importance of synthetic chemistry in ... ↗
• Drug Synthesis - an overview ↗
• Pharma Synthesis ↗
• Understanding the pharmaceutical value chain ↗
• A comprehensive guide to the pharmaceutical supply chain ↗
• Where the Pharma Value Chain Meets the Supply Chain ↗
• Pharmaceutical Market Size And Share Report, 2026-2033 ↗
• Pharmaceutical Market Size to Project USD 3219.76 Billion by 2035 ↗