1. ↑ Hydroxypropyl Methylcellulose. Binds ingredients; stabilizes emulsions; film former; gelling & coating agent. Used as an inactive ingredient in the pharmaceutical industry. It has also been used as a rate-controlling polymer for sustained-release dose forms. It has a high viscosity and is often used in ophthalmic preparations as artificial tears for dry eyes. In the US, it is available over-the-counter (OTC) in such products as Isopto Tears and Nature’s Tears.