H. Remili et al., MICROBIOLOGICAL QUALITY OF SPRAY-DRIED PHARMACEUTICAL PLANT-EXTRACTS, European journal of pharmaceutical sciences, 1(5), 1994, pp. 265-268
Eighty-two spray-dried pharmaceutical plant extracts were analyzed in
order to determine the profile of their microbial contamination. This
profile seems to be qualitatively similar to that of the raw plant pow
ders described in the literature. Quantitatively spray-dried extracts
were less contaminated, but the total viable bacterial aerobic count r
emained relatively high, exceeding 10(3) CFU/g in 35 samples. The most
frequently identified species were Gram-positive rods (56/82). Intest
inal enterobacteria (growing at 44-degrees-C) were never displayed, bu
t enterococci and group D streptococci were identified in 20 samples,
and were considered as a better index of a faecal contamination. Staph
ylococcus aureus (1/82) and Pseudomonas aeruginosa (none) are unlikely
contaminants for this kind of product. Moreover, in view of the low w
ater content of the product (never exceeding 4%) the contaminating bac
teria can be estimated to be in a static state. According to the obser
ved profile of contamination, the original plant seems to be the main
source of contamination of the spray-dried product. The spray drying p
rocess (including the extraction) insufficiently reduces this initial
contamination. Thus efforts must be developed in order to optimize bot
h the process and the selection, control and cleansing of the original
material.