If the leaves are turning brown and dry starting at the tips and moving back, it's more likely that you might be underwatering your
plant. (I have that problems in the office I'm at right now.) Overwatering causes black spots on the leaves.
The other things to check for might be mealy bugs, maybe? I know root mealy bugs like aloes, but I've never had a problem with that.
And I do have several aloes that 'shed' their bottom leaves. Part of that was the leaves got too large and heavy, and cut themselves on the edges of the pots they were in. (Does that make sense?)
I hope I helped, if not, just ignore what I said!
Reu