Recent expansions of novel strategies towards the drug targeting into the brain

Abstract

The treatment of central nervous system (CNS) disorders always remains a challenge for the researchers. The presence of various physiological barriers, primarily the blood–brain barrier (BBB) limits the accessibility of the brain and hinders the efficacy of various drug therapies. Hence, drug targeting to the brain, particularly to the diseased cells by circumventing the physiological barriers is essential to develop a promising therapy for the treatment of brain disorders. Presently, the investigations emphasize the role of different nanocarrier systems or surface modified target specific novel carrier system to improve the efficiency and reduce the side effects of the brain therapeutics. Such approaches supposed to circumvent the BBB or have the ability to cross the barrier function and thus increases the drug concentration in the brain. Although the efficacy of novel carrier system depends upon various physiological factors like active efflux transport, protein corona of the brain, stability, and toxicity of the nanocarrier, physicochemical properties, patient-related factors and many more. Hence, to develop a promising carrier system, it is essential to understand the physiology of the brain and BBB and also the other associated factors. Along with this, some alternative route like direct nose-to-brain drug delivery can also offer a better means to access the brain without exposure of the BBB. In this review, we have discussed the role of various physiological barriers including the BBB and blood-cerebrospinal fluid barrier (BCSFB) on the drug therapy and the mechanism of drug transport across the BBB. Further, we discussed different novel strategies for brain targeting of drug including, polymeric nanoparticles, lipidic nanoparticles, inorganic nanoparticles, liposomes, nanogels, nanoemulsions, dendrimers, quantum dots, etc. along with the intranasal drug delivery to the brain. We have also illustrated various factors affecting the drug targeting efficiency of the developed novel carrier system.

Keywords:

• brain
• drug targeting
• nanocarrier
• BBB
• liposome
• intranasal drug delivery

Acknowledgments

The authors want to acknowledge Rungta College of Pharmaceutical Sciences and Research, India for providing the necessary facilities for the compilation of the work. We also want to show our gratitude to Patel College of Pharmacy, India for providing the necessary literature. The authors want to extend the gratitude to the Deanship of Scientific Research and their helpful team of employees at Helwan University, Cairo, Egypt for their support.

Author contributions

Conceptualization, Dr. Amit Alexander; Literature collection, Dr. Ajazuddin; Writing, Mukta Agrawal; Formal analysis, Dr. Ahmed M Shehata and Dr. Mahmoud A Shaker; Supervision, Dr. Amit Alexander and Dr. Syed Ata Ur Rahman; Review and Editing, Dr. Sabahuddin Siddique and Dr. Amit Alexander; and Funding acquisition, Dr. Mohi Iqbal M Abdul and Dr. Mohamed A. Shaker. All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.