Pectinic acid, a novel excipient for production of pellets by extrusion/spheronisation: preliminary studies.

A very low soluble pectin-derivative (pectinic acid, degree of methoxylation 4%) was found to be well suited as an excipient for pelletisation by extrusion/spheronisation. Formulations containing pectinic acid and lactose in the following ratios were evaluated: 99/1, 80/20, 50/50 and 20/80. The capacity as an extrusion aid was found to be high; even formulations containing only 20% pectinic acid resulted in nearly spherical pellets. All pectinic acid pellets were mechanically stable, had an aspect ratio of approximately 1.15-1.20 and released 30-60% of a low solubility model drug within 15 min both in simulated gastric acid (0.1M HCl) and intestinal fluid (phosphate buffer pH 6.8).