Does the Future of Solubility Lie in HME?

Hot Melt Extrusion creates crystalline structures with finer particles. Anjali is principal research scientist at Boehringer Ingelheim.

Anjali Angrawal, principal research scientist at Boehringer Ingelheim, discusses the Hot Melt Extrusion process, which creates crystalline structures with finer particles in this interview.

Assessing and improving how effectively drugs react inside the human body can be a complex area for drug developers, with a range of techniques existing to ensure compounds can be properly dispersed.
One such strategy which has caught the eye of pharmacists in recent times is hot melt extrusion (HME).

Despite having a strong history in the production of plastics and even food products, the concept is now a big area of debate in drug development. Essentially, the technique involves pushing materials through a die under controlled conditions to create a new product.

Some may wonder what impact such an activity would have on solubility, but a closer look at the methods highlight the benefits it can offer. Talking to Pharmaceutical Technology, Peter von Hoffman, general manager of engineering plastics at Coperion, said the forces generated through HME can transform the structure of large molecular ingredients and create a crystalline structure with finer particles – making products more soluble. Pharmaceutical firms also have the option to amend the release rate of their drugs by adding other ingredients to the products in the extruder.
Such benefits however raise a question – will HME become a more widespread technique for improving solubility in the near future? Well, Hoffman told the website that developments in technology have made it easier for companies to rethink their production processes and adopt the policies into their operations.

These advantages could be why there appears to be signs that the word is spreading on the benefits of HME across the globe. Earlier this month, Thermo Fisher Scientific and chemical giant BASF confirmed they are set to take their promotion of the concept to China.

The firms are set to establish a joint workshop which, from now until the end of October, will offer Chinese pharmaceutical manufacturers and institutes the chance to learn more about the HME process.

In a statement, the companies could not help but extol the virtues of the concept when it comes to solubility. They added: "This technology can be used to prepare taste-masked pellets and special dosage form designs, including films, rods and hollow cylinders.

"Without any aqueous and/or organic solvents during the extrusion, drying is unnecessary for this process, hence the probability of significant degradation is relatively small due to the shortened process time."

As well as offering a range of advice on HME, training sessions will also see participants get their hands on free excipients and instruments designed for extrusion.

"ThermoFisher is providing its cGMP-compliant Hot Melt Extruder for manufacturing and mini-lab to Shanghai, it can perform a trial with only 5g of materials," the statement outlined. "BASF will provide innovative materials specially designed for HME technology – Soluplus and many other excipients that are already widely used in solid dispersion."

With big-hitters such as Thermo Fisher Scientific and BASF backing HME, it is safe to say that the area is not one that the pharmaceutical industry is set to lose interest in anytime soon. Drug formulation is a complex area rife with difficulties and a range of ideas, from nano-crystal formation to the implementation of silico tools.
While it would be unwise to suggest that HME could spell an end to any other theories on drug development and solubility, it would appear its star is well in the ascendancy. After all, any concept that makes the latest compounds more effective – and easier to swallow – is likely to have a big future.