title: Design and development of antisense drugs.
abstract: BACKGROUND
  With the advent of nucleic acids as therapeutic molecules, the traditional drug discovery and development process has undergone a radical change. Because nucleic acids target complementary sequences and the recognition is on the basis of Watson-Crick base pair formation, the specificity of the whole process is high. The unwanted side reactions, which are a common phenomenon observed with small molecules, are thus cut down.
  
  
  OBJECTIVE
  The objective of this review is to look at the concept of antisense oligonucleotides as nucleic acid medicines and trace the history of drug molecules based on this concept that are at various stages of advancement. The problems encountered in the development process and the possible delivery routes are critically analyzed.
  
  
  CONCLUSIONS
  Although specificity and selectivity are the key features of antisense oligonucleotides, the need to target the right tissues and reach the nucleus remains a challenge to overcome.
authors.affiliation: National Institute of Pharmaceutical Education and Research (NIPER), Department of Biotechnology, Sector 67, SAS. Nagar, 160 062 Punjab, India +91 172 2214 682 ; +91 172 2214 692 ; ipsita@niper.ac.in.
authors.forename: Ravinder
authors.initials: R
authors.lastname: Malik
authors.forename: Ipsita
authors.initials: I
authors.lastname: Roy