For a pack designed for running that wont bounce I have to recommend the Salomon Skin series of packs.
The skin 5 is excellent for water, water treatment, some snacks, a shell and some other essentials like a headlamp, first aid, a camera and compass etc.
The Skin 12 will comfortably carry just about anything you could think about carrying for a long day. There are people on here who could fit their overnight gear in it. I like it over the 5 when I want an insulation piece and maybe some larger food items.
There are other sizes as well, but I have no first hand experience to contribute.
Don't play the gram counting game when it comes to a pack for running. Get one designed for the task as comfort will come more so from weight distribution and reduced bounce than weight on your shoulders.