When I learned drug discovery long time ago, I read the article about Role of five which is a rule of thumb to evaluate druglikeness.
You can read nice review about the druglikess scores in following URL.
( Written in Japanese ;-) )
View at Medium.com
By the way, recently there are many articles which are describing about beyond the Role of five . I read an article published from JMC, reported by researcher of NIB.
The author analyzed the change over time of properties such as MW, logP, HBA, HBD, TPSA and NumAromaticRing.
In page B, the author reported comparison between experimental and calculated (StarDrop, Pomona, Moka, Crippen) value of LogP which is determined in Novartis. And the experiments shows that StarDrop gave the lowest variability between measured and calculated logP. Most of tools overestimate in high log P area but stardrop does not. It worth to know that clogp is largely affected by computational tools.
In Table5 shows analysis of FDA approved oral NCEs from 1998 to 2017. Mw, RotBm and #ArRNG showed significance.
For example 90th percentile of Mw is 571.0 compared to 1997 90th percentile 470.3. It dramatically increased!
And also 90th percentile of #ArRNG is 4 compared to 1997 90th percentile 3.
Mw is changed dramatically I think. Fig 6 shows Number of ratio of MW in approved drug in each time period. This figure shows tendency to decrease of ratio of the drug which has MW <= 500.
By the way, HBD is not changed.
The author discussed about why size (MW) is matter and described that higher molecular weight is not be indicator of druglikeness but be estimator of synthetic accessibility.
To synthesize molecule with high molecular weight, it needs more building blocks and / or longer synthetic steps. So it is needed more effort to SAR expansion in medicinal chemistry projects.
Ro5 is easy to understand and reasonable role for medicinal chemistry but it is changing. Recently there are many modalities for drug discovery.
Changing role is needed long time and many efforts…..
More details are described in the article. It is informative for me.