OBJECTIVETo evaluate in vivo pharmacokinetics of Ophiopogonis Radix polysaccharide MDG-1 oily suspension injection prepared with different prescriptions in rats, and explore the feasibility of the long-acting drug delivery of MDG-1 Injection by using the oily suspension drug release system.

METHODMDG-1 microparticles were prepared by the anti-solvent precipitation method. Their size and size distribution were characterized. Castor oil with a high viscosity or aluminum stearate were added into soybean oil with a low viscosity, in order to prepare oily media with different viscosities, detect their rheological properties and screen out superior prescriptions for in vivo evaluation.

RESULTThe average size of microparticles was 21.81 microm, and the span between them was 2.63. The in vivo evaluation was conducted for prescriptions of mixed oil (soybean oil/castor oil, 2: 3) and soybean oils gelled by 2% and 4% aluminium stearate. Among them, the prescription of soybean gelled by 4% aluminium stearate could significantly reduce C(max) and prolong the apparent t1/2, with the MDG-1 release time of several days.

CONCLUSIONIt is feasible to achieve the long-acting MDG-1 drug delivery by using oily media with a high viscosity.