Pharmaceutical Manufacturing Handbook: Production and

912 PHARMACEUTICAL PREFORMULATION
Depending on the hygroscopicity based on the EMC, various drug and excipients
are classifi ed in four groups (Table 16 ).
Figure 8 also shows an example of moisture uptake for four selected excipients
as a function of relative humidity. Depending on the hygroscopicity of the exscipients,
the uptake behaviors are quite variable. Excipients such as microcrystalline
cellulose (MCC) and starch can pick up signifi cant amounts of water at relatively
low relative humidity. Since this water is not present as a hydrate, it is potentially
free to interact with a drug.
TABLE 16 Classifi cation of Hygroscopicity and Example Pharmaceutical Excipients
Type II:
Type II:
Type I:
Slightly
Moderately
Type IV:
Nonhygroscopic
Hygrocopic Hygroscopic Very Hygroscopic
No MC change No MC change Not more than 5% Increase of MC at RH
below RH 90% or below RH MC change below 40 – 50% or more
less than 20% MC 80% or less RH 60% or less than 70% MC
changes at RH than 40% MC than 50% MC changes above RH
90% after 1 week changes at RH changes at RH 40% after 1 week
storage
80% after 1 70% after 1 week storage
week storage storage
Lactose USP MCC
Examples
HPC
Povidone
Dicalcium phosphate Sucrose, dextrose HPMC
Sodium starch glycolate
Ethylcellulose Poloxamer 188 Bentonite Polyplasdone XL
Magnesium stearate PEG 3350 Pregelatinized starch Sorbitol
CAP
Starch USP, Corn
Gelatin USP
CMC Na
Moisture content (%)
60
50
40
30
20
10
0
Lactose USP, anhydrous
Cellulose acetate phtahlate NF
Magnesium aluminum silicate NF
Povidone USP
0 20 40 60 80 100
Relative humidity(%)
FIGURE 8 Profi les of moisture uptake for four selected excipients as function of relative
humidity.