Sub WithoutDupes()
r = 2
Do Until Range("A" & r).Value = ""
Range("D" & r).ClearContents
For C = 1 To 2
DataSet = Split(Cells(r, C).Value, ",")
For D = 0 To UBound(DataSet)
If C = 1 And Range("D" & r).Value = "" Then
Range("D" & r).Value = DataSet(0) & ","
Else:
resultset = Split(Range("D" & r).Value, ",")
DataExists = ""
For Z = 0 To UBound(resultset)
If DataSet(D) = resultset(Z) Then
DataExists = "Yes"
Exit For
End If
Next
If DataExists <> "Yes" Then
Range("D" & r).Value = Range("D" & r).Value + DataSet(D) & ","
DataExists = ""
End If
End If
Next
Next
Range("D" & r).Value = Left(Range("D" & r).Value, Len(Range("D" & r).Value) - 1)
r = r + 1
Loop
End Sub


Sub WithDupes()
r = 2
Do Until Range("A" & r).Value = ""
Range("C" & r).ClearContents
Range("C" & r).Value = Range("A" & r).Value & "," & Range("B" & r).Value
r = r + 1
Loop
End Sub