Impact of lubrication on key properties of orodispersible minitablets in comparison to conventionally sized orodispersible tablets

Orodispersible minitablets (ODMTs) offer several benefits like easy swallowability, dose flexibility and simple manufacturing through direct compression. In this study, the effect of lubrication on five different co-processed excipients (Ludiflash®, Parteck® ODT, Prosolv® ODT G2, galenIQ™ 721 and SuperTab® 50 ODT) has been studied for orodispersible tablets (ODTs) with 11.28 and 2 mm in diameter. External lubrication was compared with internal lubrication using 0.5 %, 1 % or 2 % magnesium stearate or 1 %, 2 % or 4 % sodium stearyl fumarate. Mechanical strength and disintegration time of the ODTs were evaluated beside the lubrication efficiency. Especially mannitol-based co-processed excipients show strong dependency of the lubricant concentration whereas both ODTs and ODMTs and minitablets with isomalt showed comparable properties for both lubricants and their concentrations. Sodium stearyl fumarate is considered as the preferred lubricant for ODMTs as it showed a higher lubrication efficiency and less negative impact on disintegration time. External lubrication exhibited higher tensile strength for plastic materials, but increased the disintegration time, particularly for ODMTs due to the high specific surface where the lubricant is applied. In general, this study has demonstrated that minitablets require higher lubricant concentrations than conventionally sized tablets.