Abstract: The invention concerns novel pharmaceutical preparations containing (A) an extract of the mollusc Perna canaliculus, a mussel which is found on the shores of New Zealand, and (B) a pharmaceutically active substance, especially medicaments having anti-phlogistic, antipyretic and/or analgetic action, which, when taken per se, may cause as a side effect irritation of the gastro-intestinal mucosae and possibly the formation of ulcers. The addition of a mollusc extract according to (A) to the said medicaments has a gastro-protective action, in that the occurence of the said side effects is prevented or diminished. The component (A) is preferably used as a dry powder of the whole of the flesh of the mollusc or a dry powder obtained from the gonads thereof. In a typical preparation according to the invention an extract of the gonads is e.g. combined with acetyl-salicylic acid. The preparations may contain the 2 components in one and the same dosage unit form, e.g. a capsule or in 2 different ones, e.g.