Comparative evaluation of powder and tableting properties of low and high degree of polymerization cellulose I and cellulose II excipients

Low and high degree of polymerization (DP) cellulose II powders have been prepared from Avicel® PH-102 and Solka Floc® 40NF (low and high DP cellulose I powders, respectively), respectively, by treatment with sodium hydroxide (5N) for 24 h and their powder and tableting properties investigated. Cellulose II powders, compared to the respective cellulose I counterpart, exhibited lower crystallinity, true density, and specific surface area. They were denser and showed higher moisture uptake. The Heckel analyses revealed both low and high DP cellulose II powders to be less ductile than the low DP cellulose I powder and more ductile compared to the high DP cellulose I powder. The crushing strengths of low and high DP cellulose II powders were comparable to that of the high DP cellulose I powder but lower than the low DP cellulose I powder. When compressed to comparable crushing strengths, the low and high DP cellulose II compacts disintegrated faster in comparison to the corresponding cellulose I compacts. Low DP cellulose I and II powders, compared to the high DP cellulose I counterparts were more sensitive to magnesium stearate. Magnesium stearate decreased the disintegration times of low DP cellulose I compacts but had no effect on the low and high DP cellulose II and high DP cellulose I compacts. In conclusion, low and high DP cellulose II powders, despite their different powder properties, show similar tableting properties, leading to the formation of rapidly disintegrating compacts. The low and high DP cellulose I excipients, in contrast, differ in their powder properties as well as tableting characteristics.