Oral Delivery of Proteins and Peptides: Concepts and Applications - Challenges in Delivery of Therapeutic Genomics and Proteomics - page 497

l  1200 cps with 1.0% solution
l  0.75 g/cm 3 in bulk
l pH 6.5-8.5
l  water
l White to faint yellow, odorless, hygroscopic
powder or granular material having faint paper-like
taste

l In general, shows very good stability with monovalent
salts; with divalent salts, good to marginal; with
trivalent and heavy metal salts, poor, resulting in
gelation or precipitation
l In CMC solutions offers good tolerance of water-
miscible solvents, good viscosity stability over the pH
4-10 range, compatibility with most water-soluble
nonionic gums, and synergism with HEC (hydroxy
ethyl cellulose) and HPC (hydroxy propyl cellulose)
l Most CMC solutions are thixotropic; some are strictly
pseudoplastic
l A reversible decrease in viscosity at elevated
temperatures shown in all solutions; CMC solutions
lack yield value
l Solutions susceptible to shear, heat, bacterial, enzyme,
and UV degradation
l Good bioadhesive strength
l Cell immobilization via a combination of ionotropic
gelation and polyelectrolyte complex formation (e.g.,
with chitosan) in drug delivery systems and dialysis
membranes

Hydroxypropyl cellulose partially
substituted polyhydroxy propylether
of cellulose HPC (cellulose 2-
hydroxypropyl ether) empirical
formula: (C 15 H 28 O 8 ) n

l Grades: Klucel EF, LF, JF, GF, MF, and HF
l MW 6  10 4 -1  10 6
l  4-6500 cps with 2.0% aqueous solution
l pH 5.0-8.0
l  0.5 g/cm 3 in bulk
l Soluble in water below 38°C, ethanol, propylene
glycol, dioxane, methanol, isopropyl alcohol,
dimethyl sulfoxide, dimethyl formamide, etc.
l Insoluble in hot water
l White to slightly yellowish, odorless powder

l pH best between 6.0 and 8.0
l Solutions of HPC susceptible to shear, heat, bacterial,
enzymatic and bacterial degradation
l Inert and shows no evidence of skin irritation or
sensitization
l Compatible with most water-soluble gums and resins
l Synergistic with CMC and sodium alginate
l Not metabolized in the body
l May not tolerate high concentrations of dissolved
materials and tend to be salting out