酸化マグネシウム錠の分割および分割錠の安定性評価

抄録

Tablet splitting, an important task of the pharmacist, is performed at hospitals and health insurance pharmacies. Although magnesium oxide tablets have no score line, the accuracy of their division is not assured. Furthermore, as magnesium oxide strongly absorbs moisture, the stability of half-tablets is unknown when stored in one-dose packages. The variation and loss when splitting magnesium oxide 500 mg tablets by using a tablet-divider were evaluated. The stabilities of split tablets after storage in one-dose packages at 75％RH were evaluated through the analysis of weight change, disintegration, and dissolution. The variation in half-tablets of magnesium oxide 500 mg tablets was 5.5 ± 4.4％ and the loss of almost all tablets was below 1％. Although the weight of the half-tablets increased when preserved in one-dose packages, this was related to the quantity of magnesium oxide stored in one-dose packages and not on the splitting of tablets. The disintegration time of half-tablets was prolonged by increased moisture absorption, but the disintegration time of split tablets was shorter than that of whole tablets when the same quantity of moisture was absorbed. The dissolution rate was similar among split tablets and whole tablets. Magnesium oxide tablets can be administrated as a split tablet, but caution should be exercised regarding prolonged disintegration time. Pharmacists should be careful when using half-tablets in prescriptions.