Lipinski Rule (Pfizer Rule)

What kind of compound become drugs ? 

The drug follow the Lipinski Rule (Pfizer Rule) 

1- Substance should have molecular weight of 500 or less. 

2- It should be fewer than five H-bond donating function and fewer then and ten hydrogen bond accepting function. 

3- The substance should be calculated LogP between 1 and 5.

Where LogP = Partial Coefficent (P) 

   P =  [Water/Aqueous] / [Octanol]