What Is Hot-Melt Extrusion Technology?

All you need to know about

HOT MELT EXTRUSION TECHNOLOGY

Also known as HME, Hot-melt extrusion is one of the most widely applied processing technologies in the plastic, rubber and food industry.

Today this technology has found its place in pharmaceutical manufacturing because of its fast and efficient solutions.

Hot-melt extrusion technology was first utilized in the plastic industry in the 1930s, mostly in the plastic industry in the production of products such as bags, sheets, and pipes.

The many advantages of HME over conventional solid dosage formmanufacturing have piqued the interest of the pharmaceutical industry and academia as a novel drug delivery technology.

This innovative technology has beenshown to be extremely robust and a viable method of producing many different drug delivery systems, including implantable reservoirs, pellets, films, capsules and tablets.

The word ‘extrusion’ is derived from the Latin ‘extrudere’, which literally means to press out or to drive out.

It is the process of forming a new material by forcing a raw material or mixture with a rotating screw through a hole or orifice.

All done under set conditions such as temperature, pressure, rate of mixing and feed-rate, for the purpose of producing a stable product of uniform shape and density

At the most fundamental level, an extruder consists of a platform that supports a drive system, an extrusion barrel, a rotating screw arranged on a screw shaft and an extrusion die for defining product shape.

The extruder must be able to rotate the screw(s) at a selected speed, while compensating for the torque generated from the material being extruded.

The extudate may be shaped into tablets, rods, pellets, or milled and mixed with other extra-granular excipients for different purposes.

The single screw extrusion, however, does not provide the high mixing capability of a twin-screw machine, and therefore is not the preferred approach for the production of pharmaceutical formulations.

Dispersing and mixing of drugs with other ingredients involve breaking the aggregates of the minor drug particles. In order to achieve this, a critical amount of force must beapplied during the process.

This force cannot be achieved with the single-screw, but the twin-screw extruder with its corotating or counter-rotating screws wouldprovide the high energy necessary.

Another significant design variable is whether the two screws are intermeshing or non-intermeshing, the former being preferred due to the greater degree of conveying achievable and the shorter residence times.

Industrially, due to process practicality and the ability to combine separate batch operations into a single continuous process, twin-screw extrusion significantly increases manufacturing efficiency.

Recent FDA guidelines for the enhancement and modernization of the pharmaceutical industry has facilitated the move towards continuous manufacturing processes and the implementation of process analytical technologies (PAT) to monitor, control and understand manufacturing processes. These are achievable with HME technology.

What are the Main Objectives of HOT MELT EXTRUSION?

To increase the drug's dissolution rate and bioavailability• A drug’s dissolution rate refers to the duration of

it being active inside the body once taken.

• This makes a drug’s pharmaceutical effect last longer in the body.

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To control or modulate drug release

• Controls how soon a specific drug is released once introduced in the body.

• Example: The time it takes for a soft gel capsule’s outer membrane/covering to dissolve so the actual drug can go into the body’s blood circulation.

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To mask the drug’s taste

• Certain chemicals make some form of drugs taste undesirable.

• With the help of HME, these drugs can be taste masked

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To stabilize the API

• Active Pharmaceutical Ingredient (API) refers to a substance or mixture used in manufacturing a product that causes the direct effect on the identified disease diagnosis.

• Higher API = Increased drug potency

• Certain infectious disease conditions require huge doses of antibiotics that have higher API. Hot melt extrusion can help develop higher generation medicines to combat a wide array of complex illnesses.

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Here are the advantages of HME over traditional

pharmaceutical processing techniques

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Faster and Efficient Production• Reduces production time

• Fewer chemical processing steps

Solvents are not necessary

• The presence of residues in finish products may reduce its stability and potency. Hot melt extrusion doesn’t require the use of solvents so expect longer shelf life and improved drug stability

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Closed processing

• Prevent cross contamination

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Capacity to increase API content• With hot melt extrusion, API can be increased

more than 50%.

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Content Uniformity

Hot-melt extrusion offers improved content uniformity, due to the intense mixing and agitation achieved.

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Cost Effective

Hot-melt extrusion is more cost effective, because the polymers serve multiple purposes so there are less number of excipients required.

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Thermodynamic Stability

There's greater thermodynamic stability with hot-melt extrusion compared to other hot-melt methods, with less of a tendency towards recrystallization.

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The pharmaceutical industry is going through a period of unprecedented change that has been brought about by a number of factors.

Notably, globalization of the industry, increased risk/cost associated with the development of new drug compounds and patent expiry on numerous high revenue drugs are the most compelling factors.  As a result, the demand for new drug compounds to bridge the gap in lost revenue within shorter timeframes is increasing significantly.

Hot melt extrusion is an emerging drug delivery technology that is currently being investigated bythe industry as a suitable method for the production of solid drug dispersions exhibiting enhanced solubility in gastrointestinal fluids.

This presentation was brought to you by Indemax, Inc, a manufacturer or hot melt equipment and hot melt hoses used

in hot-melt extrusion technology.

Visit www.indemax.com for more information and to order hot melt parts.