Finding high quality beginning compounds is a critical job at the start of the lead generation
stage for multi-target drug discovery (MTDD). Designing hybrid compounds as selective multitarget
chemical entity is a challenge, opportunity, and new idea to better act against specific multiple
targets. One hybrid molecule is formed by two (or more) pharmacophore group’s participation. So,
these new compounds often exhibit two or more activities going about as multi-target drugs (mtdrugs)
and may have superior safety or efficacy. Application of integrating a range of information and
sophisticated new in silico, bioinformatics, structural biology, pharmacogenomics methods may be
useful to discover/design, and synthesis of the new hybrid molecules. In this regard, many rational
and screening approaches have followed by medicinal chemists for the lead generation in MTDD.
Here, we review some popular lead generation approaches that have been used for designing multiple
ligands (DMLs). This paper focuses on dual- acting chemical entities that incorporate a part of two
drugs or bioactive compounds to compose hybrid molecules. Also, it presents some of key concepts
and limitations/strengths of lead generation methods by comparing combination framework method
with screening approaches. Besides, a number of examples to represent applications of hybrid molecules
in the drug discovery are included.