Effect of Polymer Molecular Weight on Nanocomminution of Poorly Soluble Drug

Figures & data

FIG. 1  Chemical structures of drug (itraconazole) and polymeric stabilizer (HPC).

TABLE 1  Molecular weight of hydroxypropyl cellulose (from the manufacturer)

Designations	H10	H15	H20	H25	H30	H35	H50
n	7,200	10,400	12,700	17,000	18,800	21,900	28,800
/n	1.67	1.63	1.61	1.65	1.72	1.71	1.93
p	11,200	15,250	18,700	26,750	30,000	34,000	49,000

TABLE 2  Volume-averaged mean particle sizes (μ m) of drugs as a function of nanocomminution (3–4 days) and their changes after comminution (30–60 days) in the presence of HPCs having different molecular weights.

PolymersTime elapsed	H10	H15	H20	H25	H30	H35	H50
3 hr	0.44	0.44	0.44	0.47	0.53	0.52	0.64
6 hr	0.37	0.37	0.36	0.39	0.54	0.5	0.47
9 hr	0.34	0.33	0.33	0.36	0.40	0.38	0.41
1 day	0.14	0.16	0.17	0.23	0.34	0.39	0.33
2 days	0.16	0.15	0.13	0.14	0.12	0.13	0.18
3 days	0.11	0.11	0.11	0.10	0.11	0.17	0.13
4 days	0.11	0.11	0.11	0.11	0.11	0.12	0.24
30 days	0.11	0.11	0.10	0.10	0.10	0.11	0.14
45 days	0.11	0.11	0.11	0.10	0.10	0.13	0.13
60 days	0.11	0.10	0.10	0.10	0.10	0.11	0.12

FIG. 3  Particle size distribution on the redispersion of dry itraconazole powders having HPCs of different molecular weights. The volume-averaged mean particle sizes of H10–H50 are 10.6, 14.3, 15.1, 22.7, 22.6, 17.7, and 26.0 μ m, respectively.

FIG. 4  Amount of polymer (HPC) adsorbed on the surface of itraconazole particles obtained from thermal gravimetric analysis.

FIG. 5  SEM micrographs of itraconazole particles processed by nanocomminution (4 days) in the presence of HPC.

FIG. 2  Volume-averaged mean sizes of itraconazole particles milled in presence of HPCs having different molecular weights.