Thiolated polymers or designated thiomers are mucoadhesive polymers, which contain thiol functional groups on side chains. The low molecular mass thiol group compounds are covalently bonded to a polymeric backbone. The polymeric backbone is comprised of well-established and safe polymers such as chitosan or poly(acrylic acid). It has been demonstrated in various studies, that thiomers exhibit mucoadhesive (1), permeation enhancing (2), controlled release (3), as well as enzyme (4) and efflux pump inhibitory properties (5). These features make thiomer technologies potentially useful for noninvasive delivery including the oral, nasal, buccal, and vaginal routes. Thiomers can be directly compressed to into tablets or to produce solutions for administration. Thiomer-based micro-and nanoparticles have been developed, and this monograph describes the technology, its applicability for controlled release and the current research and development and intellectual property status of the technology.