Oral Controlled Delivery Of Poorly Water-Soluble Drugs

By Jim Huang, PhD, Founder & CEO, Ascendia Pharmaceuticals

In the pharma industry, there is a very high failure rate in new drug development. Only one in 5,000 discovery compounds will reach the market. Most failures in early development are mainly due to drug toxicity, safety, and efficacy issues. A significant increase in the percentage of new chemical entities (NCEs) with poor physical, chemical, and biopharmaceutical properties (BCS II and IV) in the drug pipeline has played a significant role in attributing to those high failure rates. Around 50% of drugs on the market and nearly 90% of molecules in the discovery pipeline are poorly water soluble. Poor solubility can lead to low bioavailability, resulting in suboptimal drug delivery, ineffective drug efficacy, and side effects. As a result, various drug delivery nanotechnologies, such as nano-suspensions, lipid microemulsions, nano-emulsions, and amorphous solid dispersions, have been found critical in overcoming these bioavailability challenges faced by the pharma and the biotech industries.

In addition, because immediate-release formulations normally having a wide fluctuation of drug plasma concentration and causing unwanted toxicity and poor efficiency, oral controlled-release formulations, which could maintain a steady concentration of the drug in the plasma within the therapeutic index, have been adapted for early drug development to overcome compound toxicity issues (Figure 1). Controlled-release formulations can optimize the pharmacokinetic and pharmacodynamic properties of drugs, and thus can improve the safety and efficacy of NCEs that otherwise might fail due to safety reasons. In addition, controlled-release dosage forms have proven very useful in lifecycle management of approved drugs via NDA 505(b)(1) or 505(b)(2) regulatory pathways. Reformulation of immediate-release dosage forms with multiple daily doses into a once-daily modified-release product can simplify dosing regimens, improve patient compliance, and enhance product safety.