Hydrogels in Drug Delivery of Hydroxypropyl Methylcellulose
There are more than 100 prescription drugs in the US market, in which one excipient is commonly used: hydroxypropyl methylcellulose (HPMC). Although water soluble, this polymer provides gelling properties when exposed to an aqueous environment. HPMC with different degrees of substitutions is used in tablet form to control the release of the drug over a longer period. Two features enable the HPMC to function as a controlled delivery system. First, it is very hydrophilic due to its hydroxypropyl c