CNS drug targeting: have we travelled in right path?

Background: Brain disorders, their prevalence and central nervous system (CNS) targeting are now at the rise. However, complexities of blood brain barrier (BBB) have limited the success of CNS targeting. Basic criteria necessary for passive diffusion were believed to influence the CNS drug delivery. However, often, BBB transportation has differed from the dogma of basic criteria. Purpose: This communication resets the extent to which basic criteria influence the brain delivery, through commanding examples. Further, it appraises the intervention of ABC transporters in BBB transportation, with a special emphasis on P-glycoprotein; and also brings forth the successful CNS transportation of therapeutics achieved through chimeric peptide technology. As a right path to travel, it flickers light on the novel CNS molecular drug targets/biomarkers which are specially expressed by diseased cells. Conclusion: Screening for right molecular target is of great importance for cost and time effective drug discovery process. The principle of chimeric peptide technology should be applied for CNS targeting; and every diseased cell should be screened for its biomarker. Thanks to glycan/lectin arrays technique which scans expression pattern of transporter and their possible ligands, and paves way for a new dimensional research.