Taking prescription drugs at the right time and in the right dose can have a direct impact on a patient’s health. Conversely, losing a drug or not taking it when needed can have costly consequences. By creating a system that delivers drugs that meet the needs of patients, it may be possible to solve the problem of forgetting to take drugs.
A compliance rate of 80% or higher is required for a drug to provide optimal therapeutic efficacy. However, long-term medication adherence is estimated to be around 50%.
The costs associated with someone not taking or mistaking prescription drugs are high and not just financial. 25%, health care costs are estimated at $100-300 billion.
But researchers at Rice University have developed a system that can deliver slow-release drugs based on existing microparticle technology, and may make forgetfulness a thing of the past.
The use of microparticles to dissolve and release drugs is not new. But Rice researchers used high-resolution 3D printing and soft his lithography to create more than 300 nontoxic, biodegradable biodegradable compounds that are small enough to be injected into the body using a standard hypodermic needle. I created an array of cylinders. Researchers call this technique uniform liquefaction and sealing of the particles to encapsulate the drug, or pulsing.
They developed different methods of loading drugs into microcylinders made from PLGA, a biodegradable, biocompatible polymer already used in FDA-approved therapeutic devices. By doing so, the researchers were able to change the drug release rate from 10 days to almost 5 weeks.
What researchers were trying to avoid was “first-order release,” the uneven dosing often seen in current drug encapsulation methods.
“The general pattern is that many drugs are released early on day one,” says study co-author Kevin McHugh. It could be 10 times less … it’s really a problem most of the time because day 1 doses are close to toxic or 10 times less or 4 times less or 5 minutes 1 – Insufficient to be effective at a later point in time.”
PULSED can be tailored to avoid first-order release problems and provides constant delivery of drug.
“Now you will give them [the patient] One shot and you’re ready for the next two months,” says McHugh.
Importantly, this study showed that particles ranging in diameter from 100 to 400 microns can be produced and loaded into pulsed microcylinders. Due to its large size, it is left until it dissolves. This helps focus drug treatment on specific areas.
“For toxic cancer chemotherapy, you would want to focus the toxin on the tumor rather than on other parts of the body,” McHugh said. “Our microparticles stay where you put them.
But the discovery of non-contact seals, so important to PULSED, happened almost by chance. Existing PLGA encapsulation methods have proven difficult to seal large numbers of particles, and manufacturing costs were deemed impractical.
The researchers explored alternative sealing methods and questioned whether the usual technique of sealing microparticles by dipping them in molten polymer was necessary. Instead, they suspended PLGA microparticles on a hot plate, and the top of the particles melted and self-sealed, leaving the bottom intact.
Previous studies have shown that PLGA capsules can deliver drug for up to 6 months after injection. The researchers hope that with further testing, PULSED can achieve the same results.
In the video below, the Rice University team explains why PULSED was developed, how it works, and how it can be used in clinical practice.
Rice Lab technology could deliver sustained-release drugs, vaccines over months
The study was published in a journal advanced materials.
Source: Rice University
