The central problem the special issue addresses is deceptively simple to state and notoriously difficult to solve: a large and growing share of new drug candidates dissolve poorly in water, and a molecule that will not dissolve cannot be absorbed into the bloodstream. Industry estimates routinely suggest that a substantial fraction of compounds emerging from discovery pipelines, particularly the poorly soluble molecules classified under the biopharmaceutics scheme known as BCS Class II, suffer from solubility-limited oral absorption. Particle engineering attacks this problem directly by manipulating the physical form of the active ingredient itself. Techniques such as micronization and nanonization increase the surface area available for dissolution, while controlled crystallization and the creation of amorphous solid dispersions can shift a drug from a thermodynamically stable but poorly dissolving crystal lattice into a higher-energy state that dissolves far more readily. The trade-off is stability, because high-energy forms tend to revert to crystals over time, and managing that reversion is one of the discipline’s defining challenges.

The topics listed in the call for papers make clear that solubility enhancement is only one thread of a much broader fabric. The editors invite contributions on particle engineering approaches for solubility, stability, and bioavailability enhancement; advanced formulation strategies for oral, injectable, inhalable, transdermal, and other dosage forms and advanced drug delivery systems; solid-state characterization and control; translational formulation science and scale-up of drug products; emerging manufacturing technologies in dosage form design and commercial production; and applications of Quality by Design and Process Analytical Technology in pharmaceutical formulation and manufacturing. Taken together, these themes describe the full life cycle of a medicine, from the first manipulation of a molecule’s solid form to the validated, regulated production line that turns it into a product patients can actually take.

Solid-state science deserves particular attention because it underpins nearly everything else in the field. The same active molecule can exist in multiple crystalline polymorphs, each with a distinct arrangement of molecules in the lattice and, consequently, distinct solubility, melting point, mechanical behavior, and physical stability. The most famous cautionary tale remains ritonavir, an HIV drug that in the late 1990s began precipitating in a previously unknown, far less soluble polymorph, forcing a withdrawal of the product from the market while manufacturers scrambled to understand and control the new form. Modern development therefore treats polymorph screening, salt and cocrystal selection, hydrate and solvate mapping, and amorphous-form risk assessment as foundational activities rather than afterthoughts. Analytical tools such as powder X-ray diffraction, differential scanning calorimetry, dynamic vapor sorption, and solid-state nuclear magnetic resonance allow scientists to fingerprint each solid form and monitor whether it persists unchanged through processing, storage, and the stresses of a global supply chain.

Formulation strategy then converts an engineered particle into a dosage form, and the range of options has expanded dramatically. Oral solid dosage remains the dominant route, and innovations there include amorphous solid dispersions stabilized by polymeric carriers, lipid-based formulations that present the drug dissolved within digestible excipient systems, and co-processed excipient blends that enable direct compression of difficult materials. Injectable formulations demand entirely different constraints, balancing sterility, isotonicity, viscosity, and the need for sustained-release depots that can release a drug over weeks or months from a single injection. Inhalable products must generate aerosol particles in a narrow aerodynamic size range, typically one to five micrometers, so that drug deposits in the deep lung rather than the throat, which makes particle size distribution and powder flow properties matters of clinical consequence rather than mere manufacturing convenience. Transdermal systems, meanwhile, must drive molecules through the skin’s stratum corneum barrier, relying on drug properties, adhesive chemistry, and in some cases permeation enhancers to achieve therapeutic systemic exposure.

What distinguishes the current moment, and what the special issue’s emphasis on translational science signals, is the growing recognition that a brilliant formulation in a laboratory beaker is worthless if it cannot be manufactured reproducibly at scale. Scale-up is where many promising technologies stall. Hot-melt extrusion, spray drying, and supercritical fluid processing all behave differently when a bench-top unit is replaced by industrial equipment processing hundreds of kilograms, because heat transfer, residence time distribution, and drying kinetics do not scale linearly. Translational formulation science seeks to bridge that gap by building predictive understanding of how process parameters shape final product quality, so that a formulation proven in early development can move into commercial production without years of costly rework. The guest editors’ combined affiliations, spanning a major research university, a national university with strong engineering programs, and a university with deep pharmacy traditions, reflect the collaboration between academic insight and industrial practice that this translation requires.

The explicit inclusion of Quality by Design and Process Analytical Technology in the call for papers marks how thoroughly regulatory philosophy has reshaped pharmaceutical manufacturing. Quality by Design, or QbD, inverts the traditional approach to product development: instead of testing finished batches to confirm quality, developers design quality into the product from the start by identifying critical quality attributes, mapping the process parameters and material properties that influence them, and establishing a design space within which the product is assured of meeting specifications. Process Analytical Technology, or PAT, supplies the real-time eyes and ears for that framework, using inline and at-line sensors such as near-infrared spectroscopy, Raman spectroscopy, and laser diffraction to monitor blending uniformity, granulation endpoints, drying progress, and particle size as manufacturing proceeds. The long-term destination is continuous manufacturing, in which powder flows uninterrupted from raw material to finished tablet, replacing the batch processes that have dominated the industry for a century and enabling real-time release testing that could shorten production cycles from weeks to hours.

Emerging manufacturing technologies extend this trajectory further. Additive manufacturing, including three-dimensional printing, has already produced the first FDA-approved printed drug product, a rapidly disintegrating levetiracetam tablet whose highly porous structure was impossible to achieve with conventional compression. Continuous twin-screw processing can combine feeding, mixing, extrusion, and downstream shaping in a single integrated line. Electrospinning and spray-freeze-drying open routes to nanostructured and high-surface-area solids, while microfluidic and precision particle engineering platforms promise tighter control over droplet and particle formation than bulk emulsification can deliver. Each of these technologies carries the same translational burden: it must demonstrate not only scientific novelty but also regulatory acceptability, economic viability, and robustness under the exacting conditions of commercial production, where a deviation can halt a supply line serving patients worldwide.

The timing of the special issue is significant. The pharmaceutical industry is simultaneously confronting an unprecedented wave of poorly soluble small molecules, the formulation challenges of biologics that demand injection rather than oral delivery, and growing pressure for personalized and flexible dosing. Advances in particle engineering and formulation science cut across all three fronts, determining whether a promising molecule ever reaches patients and in what form. By gathering contributions spanning fundamental particle science, advanced dosage form design, solid-state control, scale-up, and modern manufacturing and quality paradigms, the editors of the Journal of Pharmaceutical Investigation are effectively commissioning a status report on the discipline’s ability to translate molecular promise into therapeutic reality. Researchers working in these areas have until June 30, 2026, to submit their work for consideration in the January 2027 issue, and the resulting collection is likely to serve as both a snapshot of current capability and a signpost for where drug product development goes next.

For patients, the stakes of this largely invisible science are concrete. A better-engineered particle can mean a pill that works at a lower dose with fewer side effects, an inhaler that delivers more drug to the lungs and less to the throat, an injection that needs to be given once a month instead of once a week, or a medicine that remains stable in tropical climates where refrigeration is unreliable. The special issue’s agenda makes the case that these outcomes are not accidents of chemistry but the deliberate products of particle engineering, formulation design, and manufacturing science working in concert. As the deadline approaches, the field will be watching to see which laboratories and companies step forward with the translational advances that define the next generation of medicines.

Subject of Research: Translational advances in pharmaceutical dosage form development based on particle engineering and formulation science

Article Title: Special Issue: Translational Advances in Pharmaceutical Dosage Form Development Based on Particle Engineering and Formulation Science

Article References: Special Issue: Translational Advances in Pharmaceutical Dosage Form Development Based on Particle Engineering and Formulation Science. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: particle engineering, formulation science, drug delivery, solubility enhancement, bioavailability, solid-state characterization, Quality by Design, Process Analytical Technology, scale-up, continuous manufacturing, dosage forms, pharmaceutical manufacturing