Potato Starch

(Ph. Eur. monograph 0355)

Excipient.

When Starch is specified and the type is not indicated, Maize Starch, Potato Starch, Rice Starch, Wheat Starch or, in tropical countries where these are not available, Tapioca Starch may be supplied or used.

Ph Eur

Potato starch is obtained from the tuber of Solanum tuberosum L.

Very fine, white or almost white powder which creaks when pressed between the fingers.

Practically insoluble in cold water and in ethanol (96 per cent).

Potato starch does not contain starch grains of any other origin. It may contain a minute quantity, if any, of tissue fragments of the original plant.

A. Examined under a microscope using a mixture of equal volumes of glycerol R and water R, it presents granules, either irregularly shaped, ovoid or pear-shaped, usually 30-100 µm in size but occasionally exceeding 100 µm, or rounded, 10-35 µm in size. There are occasional compound granules having 2-4 components. The ovoid and pear-shaped granules have an eccentric hilum and the rounded granules acentric or slightly eccentric hilum. All granules show clearly visible concentric striations. Between orthogonally orientated polarising plates or prisms, the granules show a distinct black cross intersecting at the hilum.

B. Suspend 1 g in 50 mL of water R, boil for 1 min and cool. A thick, opalescent mucilage is formed.

C. To 1 mL of the mucilage obtained in identification test B, add 0.05 mL of iodine solution R1. An orange-red to dark blue colour is produced which disappears on heating.

5.0 to 8.0.

Shake 5.0 g with 25.0 mL of carbon dioxide-free water R for 60 s. Allow to stand for 15 min.

Examined under a microscope using a mixture of equal volumes of glycerol R and water R, not more than traces of matter other than starch granules are present. No starch grains of any other origin are present.

Maximum 20 ppm, calculated as H₂O₂.

Maximum 50 ppm.

Maximum 10 ppm.

Shake 1.5 g with 15 mL of dilute hydrochloric acid R. Filter. The filtrate complies with the limit test for iron.

Maximum 20.0 per cent, determined on 1.000 g by drying in an oven at 130 °C for 90 min.

Maximum 0.6 per cent, determined on 1.0 g.

TAMC: acceptance criterion 10³ CFU/g (2.6.12).

TYMC: acceptance criterion 10² CFU/g (2.6.12).

Absence of Escherichia coli (2.6.13).

Absence of Salmonella (2.6.13).

Ph Eur