In order to identify an appropriate drug combination, it is necessary to perform thorough biological evaluation which must be supported by a profound understanding of the molecular mechanisms involved. Another critical aspect is the determination of the optimal mass ratio of each component within a combination drug delivery system. This requires systematic research investigating
the impact of different drug ratios on the biological activity of the combination Inhibitors,research,lifescience,medical delivery systems. Recently a Canadian pharmaceutical company Celator (http://www.celator.ca/) has developed a methodical approach to assess different drug ratios within their liposomal technology resulting in the development of different liposomal formulations that are now Inhibitors,research,lifescience,medical being assessed in phase II clinical trials, namely, CPX-1 (irinotecan: floxuridine) and CPX-351 (cytarabine: daunorubicin). Such an approach needs to be extended to other combination delivery systems such as dendrimers or polymer-drug conjugates. Determination of the kinetics of
release of each drug in a multidrug combination system will be also necessary to determine the optimum ratio as one drug may affect the release profile of the other drug and Afatinib mouse thereby affect activity. Finally clinical development of these combination products is extremely challenging, due to developmental costs of designing such complex systems. However, these combination drug delivery system-based therapeutics Inhibitors,research,lifescience,medical are likely to be perceived by pharmaceutical companies as novel opportunities to extend the patent lives compared Inhibitors,research,lifescience,medical to current blockbuster drugs.
Controlled-release multiunit dosage forms (e.g., pellets, granules, or microparticles) are becoming
more and more important on the pharmaceutical market, as they provide several advantages compared to single-unit dosage forms (e.g., tablets or capsules) . With regard to the final dosage form, the multiunits can be filled into hard gelatin capsules  or be compressed into disintegrating tablets [3, 4]. The advantages of tableting multiunits Inhibitors,research,lifescience,medical include less difficulty in oesophageal transport, and thus a better patient compliance. Tablets can be prepared at a lower cost because of the higher production rate of tabletting process. The expensive control of capsules already integrity after filling is also eliminated. In addition, tablets containing multiunits could be scored without losing the controlled release properties, which allows a more flexible dosing regimen . One challenge in the production of such systems is maintaining the desired drug release after compaction as the application of compaction pressure can lead to structural changes in the film coating and consequently altered drug release . The compression-induced changes in the structure of a film coating may depend on formulation factors such as mechanical properties of the film and incorporated excipients of pellets .