Restrictions on 45 on bottom of vertical Drain Main
2018 IPC states: (assuming you are under IPC code?)

SECTION 704 DRAINAGE PIPING INSTALLATION 
704.1   Slope   of   horizontal   drainage   piping.  Horizontal drainage piping shall be installed in uniform alignment at uniform slopes. The slope of a horizontal drainage pipe shall be not less than that indicated in Table 704.1 except that where the  drainage piping is upstream of a  grease  interceptor,  the slope of the piping shall be not less than 1/4 inch per foot (2-percent slope).

TABLE 704.1 SLOPE OF HORIZONTAL DRAINAGE PIPE
(&lt;2.5": 1/4" per foot)
(3-6" pipe: 1/8" per foot) 
(>=8": 1/16" per foot)

a.  Slopes  for  piping  draining  to  a  grease  interceptor  shall  comply  with Section 704.1. 

704.3 Connections to offsets and bases of stacks. Horizontal branches  shall  connect  to  the  bases  of  stacks  at  a  point located  not  less  than  10  times  the  diameter  of  the  drainage stack  downstream  from  the  stack.  Horizontal  branches  shall connect to horizontal stack offsets at a point located not less than 10 times the diameter of the drainage stack downstream from the upper stack."

You can search the IPC for other details here:
https://www.ci.independence.mo.us/userdocs/ComDev/2018%20INTL%20PLUMBING%20CODE.pdf