Summary N- (17 - shikuropuropirumechiru - 4,5 -epokishi - 3,14 - jihidorokishi - moruhinan - 6 -iru) - phthalimide or the crystal characteristic particle of the salt which that medicine is allowed is disclosed. As for the said crystal characteristic particle, accumulating from the particle of the one whose particle diameter is small particle diameter of the point where cumulative frequency of cubic measure distribution reaches to 50% (D50) it is inside the range of 1 - 30 millimicrons, accumulating from the particle of the one whose particle diameter is small particle diameter of the point where cumulative frequency of cubic measure distribution reaches to 90% (D90) crystallinity is 80% or more with the particle diameter distribution of 90 millimicrons or less. According to the said crystal characteristic particle, while guaranteeing the retention stability of the said chemical compound, it is possible to raise the biological utilization talent of the field medicine.要約N-(17-シクロプロピルメチル-4,5α-エポキシ-3,14-ジヒドロキシ-モルヒナン-6β-イル)-フタルイミド又はその薬剤的に許容される塩の結晶性粒子が開示されている。該結晶性粒子は、粒子径が小さい方の粒子から累積して体積分布の累積頻度が50%に達する点の粒子径(D50)が1~30μmの範囲内であり、粒子径が小さい方の粒子から累積して体積分布の累積頻度が90%に達する点の粒子径(D90)が90μm以下の粒子径分布をもち、結晶化度が80%以上である。該結晶性粒子によれば、該化合物の保存安定性を確保しつつ、原薬の生物学的利用能を高めることができる。
