Hydroxybenzoates are salts or esters of hydroxybenzoic acids, which are a group of aromatic acid compounds with a benzene ring substituted with one or more hydroxyl groups and a carboxylic acid group. The most common hydroxybenzoic acids are ortho-, meta- and para-hydroxybenzoic acids, also known as salicylic acid, gentisic acid and protocatechuic acid respectively.

Hydroxybenzoates are widely used as preservatives in pharmaceuticals, cosmetics and food products due to their antimicrobial properties. They are effective against a broad range of bacteria, yeasts and molds. The most commonly used hydroxybenzoates are methylparaben, ethylparaben, propylparaben and butylparaben, which are esters of p-hydroxybenzoic acid.

In medical context, hydroxybenzoates may also be used as intermediates in the synthesis of various drugs and pharmaceutical compounds. They can act as antioxidants, stabilizers and chelating agents, helping to improve the stability, safety and efficacy of drug products. However, it's important to note that some people may have allergies or sensitivities to certain hydroxybenzoates, so they should be used with caution in such cases.