title: Effect of particle size on mixing degree in dispensation.
abstract: By using lactose colored with erythrocin, we examined the effect of particle size on mixing degree during the preparation of triturations with a mortar and pestle. We used powders with different distributions of particle sizes, i.e., powder that passed through 32-mesh but was trapped on a 42-mesh sieve (32/42-mesh powder), powder that passed through a 42-mesh sieve but was trapped on a 60-mesh sieve (42/60-mesh powder), powder that passed through a 60-mesh sieve but was trapped on a 100-mesh sieve (60/100-mesh powder), and powder that passes through a 100-mesh sieve (> 100-mesh powder). The mixing degree of colored powder and non-colored powder whose distribution of particle sizes was the same as that of the colored powder was excellent. The coefficient of variation (CV) value of the mixing degree was 6.08% after 40 rotations when colored powder was mixed with non-colored powder that both passed through a 100-mesh sieve. The CV value of the mixing degree was low in the case of mixing of colored and non-colored powders with different particle size distributions. After mixing, about 50% of 42/60-mesh powder had become smaller particles, whereas the distribution of particle sizes was not influenced by the mixing of 60/100-mesh powder. It was suggested that the mixing degree is affected by distribution of particle sizes. It may be important to determine the mixing degrees for drugs with narrow therapeutic ranges.
authors.affiliation: Department of Pharmacy, University of Tokyo Hospital, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakamura
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Yanagihara
authors.forename: Hiroko
authors.initials: H
authors.lastname: Sekiguchi
authors.forename: Michiteru
authors.initials: M
authors.lastname: Ohtani
authors.forename: Satoru
authors.initials: S
authors.lastname: Kariya
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Uchino
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Tatsuji
authors.initials: T
authors.lastname: Iga
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004339:Drug Compounding; D005505:Food Coloring Agents; D007785:Lactose; D010316:Particle Size; D011208:Powders
chemical_list: D005505:Food Coloring Agents; D011208:Powders; D007785:Lactose