Does Your Bioavailability Need a Boost?



Pharma IQ
03/29/2011

One of the major drug development hurdles is poor solubility, an estimated 40 percent of drugs are poorly soluble or insoluble in water1. As a result, a number of companies and partnerships are focussing their efforts on enhancing the bioavailability of poorly soluble compounds.

Benefits of boosting bioavailability

"Bioavailability enhancement translates into a number of practical benefits for the manufacturer, including a substantial reduction in the amount of costly active administered to the patient, as well as a significant reduction in the environmental impact of the drug product," Dr. David Hauss, principal of Hauss Associates, told Pharma IQ.

However, this really just scratches the surface of the benefits that enhancing bioavailability can bring.

Development timelines can be cut, a particular concern for a pharmaceutical industry which is facing the expiration of patents on its blockbuster drugs.

As figures cited above show, finding methods of enhancing the bioavailability of compounds will also have the potential to significantly increase the number making their way to the end of the drug development pipeline.

In addition to this, there are predictions that more companies will look to improve their generic compounds in the future, addressing issues such as low solubility and bioavailability, as drug development opportunities fall.



Innovative approaches to addressing poor solubility

A growing number of techniques are being developed to boost solubility, however there are a host of factors which must be considered before one is selected. 

Writing for PharmaTech.com, Peter G Nielsen said: "Many solubilisation technologies, including nanocrystals, liquid fill and melt extrusion, require expensive and complicated manufacturing processes and equipment."

Late last year also saw the signing of a partnership between clinical research organisation Particle Sciences and SoluBest, which saw the former become the sole US distributer of Solubest's Solumer technology.

The technique enhances bioavailability of poorly soluble compounds by using GRAS polymers to create drug/polymer complexes. SoluBest explains when they come into contact with an aqueous media "they spontaneously form colloidal dispersions", which boost bioavailability.

Particle Sciences is to offer Solumer and clinical supply manufacturing services under the new agreement.

Mark Mitchnick, chief executive officer of Particle Sciences, said: "This is a proven technology that is both cost effective and scalable.  It will find application with both NCE's and generics. "

The future for improving bioavailability

What is clear is that enhancing the bioavailability of poorly soluble compounds will continue to require much research and careful selection of techniques.

"Designing efficient drug delivery systems of poorly soluble drugs will never be a routine task with a one size fits all approach. To be successful, it is important to carefully tailor the development process to the specific characteristics of the API," Nielsen said.

He predicted that in the future there will need to be greater development of techniques which can boost the performance of individual molecules, as companies turn away from creating new compounds to enhancing their existing ones.

Nielsen also advised against pharmaceutical companies jumping in and using technologies which have not yet been fully commercialised, as these may end up costing them more in the long run.

Others, however, focus on the opportunities opened up by boosting solubility, rather than the challenges which stand in the way.

Philip Strenger, senior vice president of EMEA and global pharma for ISP Pharmaceuticals, said: "By solving the solubility dilemma, pharmaceutical companies will be able to offer better healthcare to the people of the world. And in so doing, will open up new opportunities for better business and improved profitability."

1. Nollenberger, Kathrin; Gryczke, Andreas; Morita, Takayuki; Ishii, Tatsuya, Using Polymers to Enhance Solubility of Poorly Soluble Drugs, Pharmaceutical Technology, April 1, 2009