Page 13 - controlled drug delievery

1- Aqueous Solubility & Ionization
constant

Fick’s diffusion law (for membrane diffusion):

dm = DAK (Ci - C0)
dt h

dm/dt = drug diffusion rate

D: Diffusion coefficient (depends on the drug molecular size)

AN: oDyoseasg-eWfohrmitnsunrefayceeqarueadatc.io=nK:A(Cs-C)
K: Partition coefficient (medmt brane/release medium)

CTi:hderulgocwoencrelnimtraittioonf inside the system (mostly = Cs) in a SR/CR

drug solubility to be formulated

Cs0y: sdtreugmcohnacsenbteraetnionreopuotsridteedthteombeem0b.r1a-n1e.mg/ml