Terpenes present in essential oils have been promising for studies of gastroprotective activity. A monoterpene constituent of Melaleuca quinquenervia (Cav.) S.F. Blake and Cedrus deodara Roxb. ex D.Don, α-terpineol, has gastric protective activity against models of acute injury in rodents. However, it is a lipophilic compound and has a short half-life in blood flow. Therefore, the objective of the present work was to propose polymeric polymethyl methacrylate particles to be loaded with α-terpineol, in order to improve the stability and half-life of the asset. Polymethyl methacrylate particles containing α-terpineol were synthesized, characterized and evaluated for the gastroprotective effect in models of acute injury in rodents. The formulation used for the gastroprotective activity test showed a diameter of 796.8 ± 88.34 nm, a polydispersity index of 0.532, a zeta potential of −52.5 ± 13.1 mV and an encapsulation rate of 74.07 ± 3.03. The incorporation of monoterpene in polymethyl methacrylate particles increased the gatroprotective efficacy of α-terpineol. The incorporation of α-terpineol in polymethyl methacrylate particles maintains the gastroprotective properties of α-terpineol, with a lower dose administered compared to carbenoxolone, a drug used in the treatment of lesions of the oral mucosa.