Dosage forms or pharmaceutical compositions comprise a compound having the structure of Formula IV: wherein n is a non-negative integer； wherein each Z is an oxazolidinone-containing moiety having antibiotic activity in vivo upon cleaving, wherein M is independently OR1 or NR1R2； wherein R1 and R2 are independently selected from the group consisting of H, an optionally-substituted hydrocarbyl residue or a pharmaceutically acceptable cation； wherein the compound in the dosage form or a pharmaceutical composition is present in an amount effective for treating or preventing an antibacterial infection in a mammalian subject. Methods of preparing and using these dosage forms or pharmaceutical compositions are also disclosed.
