Solid Drug Nanoparticle Technologies

The LONGEVITY project uses revolutionary Solid Drug Nanoparticle (SDN) technologies. SDNs are nanoparticles of a drug stabilised by water soluble excipients and are fundamental to the LONGEVITY blueprint.

It is with this revolutionary technology that we can facilitate effective exposure to a drug for a period between one and four months. This new innovation offers potential for rapid development at low cost and with optimal product performance. Our approach will quickly develop cost effective options to deliver high doses of active pharmaceutical ingredients.

How do they work?

Many drug compounds that are good candidates for long-acting injectables are poorly water soluble. This creates a conundrum as we need to place a lot of drug into the small volume that we are going to inject, and the injection uses water as the main vehicle. To overcome this problem, we use solid drug nanoparticles - tiny particles of the poorly soluble drug, less than 100th the width of a human hair, that are dispersed in water. This avoids the solubility problem as we don't need to dissolve the drug at all, just form a dispersion of particles that are so small that we can place a lot of them in water without blocking the injection needle.  Our formulations form a reservoir of drug at the injection site which slowly delivers drug to the bloodstream over long periods of time and avoids the need for daily pills. The ability of the nanoparticles to disperse in water is essential to their success as long-acting injectable formulations

By creating SDNs it is possible to create products that readily disperse in water and allows us to achieve a high drug loading within an aqueous medium that can then be administered by injection. Delivering this formulation by either subcutaneous or intramuscular injection may provide enough drug to offer protection against various diseases over a period of months, whilst current oral medications require daily dosing.

Our strategy

The objective for the LONGEVITY project is to repurpose pre-existing medicines as long-acting formulations. Using pre-existing oral medications is beneficial as the efficacy and toxicity of the drug is already known. This means that it is already approved for use by regulators such as the FDA, and as SDNs are nanoparticles of the drug, there are fewer regulatory processes to go through to develop an SDN product.

The excipients used with the SDN formulations are also carefully selected from the FDA CDER List of Inactive Ingredients, which is a database that documents materials that are already used in approved medicines. The properties of these non-drug excipients are well established and therefore considered a low risk for development of future medicines.

The products we aim to deliver to low- and middle-income countries will offer a much-needed alternative to daily oral medications that will simplify treatment programmes leading to much better adherence to life-saving medicines.


Solid drug nanoparticles are the bedrock of the LONGEVITY Project, and many other technologies that we are developing within CELT. They offer a solution to the long-standing problem of poorly water-soluble drug compounds that the pharmaceutical industry wrestles with constantly

Professor Steve Rannard, Co-coordinator for the LONGEVITY Project

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