How DIANT’s Continuous Manufacturing Technology Mitigates Challenges in Nanoparticle Product Development and Beyond

Lipid nanoparticles (LNPs) have emerged as increasingly versatile vehicles for targeted drug delivery, offering numerous advantages, such as improved solubility, enhanced drug stability, and reduced toxicity, compared to other drug delivery mechanisms.

As a vital component of recent COVID-19 mRNA vaccines, LNPs effectively encapsulate mRNA molecules to protect them from degradation and facilitate cell uptake. Because they protect DNA and RNA until they reach the target cells, LNPs are also quite valuable for gene therapy developers. Additionally, they have shown utility in delivering small interfering RNA (siRNA) or microRNA (miRNA) for RNA interference (RNAi) therapies that silence specific genes involved in genetic diseases, viral infections, and cancer.

Beyond their ability to effectively deliver genetic material, LNPs have many additional qualities that make them useful across a wide range of applications. As a result of their ability to enhance immune response, LNPs are being explored for delivering antigens or adjuvants as part of novel vaccine formulations against various infectious diseases. LNPs’ small size allows them to penetrate ocular barriers and deliver drugs effectively to specific parts of the eye. LNPs also have the potential to cross the blood-brain barrier, making them valuable for delivering drugs to the brain to treat neurological disorders.

Plus, LNPs are being developed to improve the absorption of oral drugs that are poorly soluble or unstable in the gastrointestinal tract and to provide controlled release of therapeutics over time during transdermal delivery.

While LNPs are excellent drug delivery mechanisms across many applications, one of the most pursued areas is oncology because LNPs can be engineered to target cancer cells, delivering chemotherapeutic drugs directly to the tumor site, sharply reducing damage to healthy tissue.

LNP encapsulation of anti-cancer drugs improves their solubility and stability and reduces toxicity. LNPs also enable combination therapy because they can simultaneously encapsulate multiple therapeutic agents, including oncology drugs, nucleic acids (such as siRNA or mRNA), and imaging agents. In addition, LNPs enable enhanced penetration and retention of a drug at the tumor site, allow for controlled release, help stimulate the immune system, and help overcome cancer cells’ multidrug resistance.

Free active pharmaceutical ingredients (API) in cancer therapeutics (API not effectively encapsulated) can pose significant patient safety concerns because chemotherapeutics that contact healthy tissue can be extremely toxic to patients.

LNPs show promise in significantly reducing side effects due to their ability to encapsulate free API. For this reason, LNPs are a strong candidate for the targeted delivery of chemotherapy agents, gene therapies, or immunotherapies directly to tumor cells.

LNPs have their physical and historical roots in liposomes, first used as delivery vehicles in the 1990s. Nanomedicines such as liposomes coated with polyethylene glycol (PEG) that encapsulate API have been highly effective in decreasing the toxic side effects of anti-cancer therapeutics. As drug delivery vehicles, liposomes can protect encapsulated substances from physiological degradation, extend the half-life of the drug, control drug release, and offer excellent biocompatibility and safety. By selectively delivering their payload to the diseased site through passive and/or active targeting; liposomes can also decrease a drug’s systemic side effects, elevate the maximum-tolerated dose, and improve therapeutic benefits.

As an example, doxorubicin is a highly effective, broad-spectrum anti-cancer drug known to cause severe and possibly life-threatening heart problems, including heart failure. These problems can occur months to years after a patient has received doxorubicin.

Doxil (PEGylated liposomal doxorubicin) was the first anti-cancer nanomedicine approved by the Food and Drug Administration in 1995. Formulated to minimize the toxicity of doxorubicin and to maintain its efficacy, Doxil encloses doxorubicin in an 80–90-nm size unilamellar PEG-coated liposome that allows the drug to stay in the bloodstream longer so that more of the drug reaches the cancer cells. Compared with free doxorubicin, doxorubicin-loaded liposomes deliver a high payload of API to a tumor site while increasing circulation time and reducing cardiotoxicity.

While LNPs are highly effective drug delivery mechanisms, they are very challenging to manufacture. Designing uniformly sized LNPs with high encapsulation efficiency requires precise tuning and optimization.

The complicated process of making doxorubicin-loaded liposomes illustrates key challenges. Typically, doxorubicin-loaded liposomes have a single lipid bilayer with a doxorubicin nanocrystal in the intraliposomal space. Many studies indicate that generic forms of liposomal doxorubicin produced by conventional batch processing have a variety of crystal morphologies and particle size distributions, which can result in inconsistencies in the safety and efficacy of these drugs.

Using a continuous manufacturing process, such as the DIANT^® Jet technology, enables better control over crystal morphology than batch processing, resulting in more uniform nanoparticles and more consistent LNP drug products.

Common LNP processing techniques include thin-film hydration, homogenization, and organic solvent injection, where solvent injection may be performed using a turbulent jet, microfluidic cassettes, or other mixing strategies.

DIANT’s ethanol injection approach forms a highly effective jet for controlling particle size and maintaining a tight particle size distribution at high throughput. DIANT’s continuous processing system is scalable from lab bench to commercialization and consists of three main stages– particle formation, concentrating/dilution/buffer exchange, and active loading. Process Analytical Technology (PAT) is incorporated at each stage, with automated controls and monitoring capabilities.

When DIANT’s continuous processing technology is used to manufacture doxorubicin, the particles enter an active loading stage after passing through the DIANT^® sp2TFF, where the doxorubicin is added into the flow stream. Compared to brand and generic versions of liposomal-doxorubicin, DIANT’s continuous manufacturing process achieves more than 95% drug encapsulation with a very uniform particle size. Given its success with doxorubicin, DIANT’s technology has the potential to offer significant quality and cost advantages in the manufacturing of other nanoparticle anti-cancer therapeutics.

DIANT’s continuous manufacturing systems include DIANT^® Jet technology, which helps simplify and streamline nanoparticle processing, making it a more efficient process. This process directly impacts particle properties and results in more uniformly sized and loaded nanoparticles.

A consistent particle profile for mRNA-LNPs, from mRNA loading to particle morphology, may create safer, more effective LNP drug products. For liposomal-doxorubicin, DIANT technology enables more effective control over crystal morphology than conventional batch processing, resulting in very spherical nanoparticles with highly consistent quality attributes. DIANT^® technology provides a clear solution to mitigate challenges in the nanoparticle product development cycle that can scale through commercial manufacturing.