Which property is not typically desired in sustained release polymers?

Sustained release polymers are designed to release an active pharmaceutical ingredient over an extended period, allowing for a more controlled and predictable therapeutic effect. Among the properties associated with these polymers, rapid dissolution is not a desired characteristic. This is because rapid dissolution would lead to a quick release of the drug, defeating the purpose of sustained release, which aims to maintain a steady concentration of the drug in the bloodstream over time.

In contrast, hydrophilicity is beneficial as it helps the polymer to absorb water, which can facilitate the controlled release mechanism. Biocompatibility is vital to ensure that the material is safe for use in the body and does not provoke an adverse immune reaction. Controlled release is, of course, a primary goal of using sustained release polymers, as it helps in maintaining therapeutic drug levels and improving patient adherence to medication regimens. Thus, rapid dissolution undermines the fundamental concept of sustained release mechanisms, making it the correct answer in this context.