Sumitomo Chemical Company, Limited

Tadao Maeda

Yoshiya Yamahira

Keiji Fujioka

Shigeji Sato

Toshio Nakamura

Hiroshi Takenaka

Terutsugu Tsuji

A process for freeze-drying a penicillin derivative of the formula: ##STR1## wherein R is a hydrogen atom or a hydroxyl group, by evaporating a frozen aqueous solution of the penicillin derivative (I) under vacuum from the frozen state to dryness, which is characterized by maintaining the temperature of the frozen solution within a range from the eutectic point of the solution determined by the electric resistance method to -8.degree. C. when the penicillin derivative of the formula (I) wherein R is a hydrogen atom is to be freeze-dried, or -10.degree. C. when the penicillin derivative of the formula (I) wherein R is a hydroxyl group is to be freeze-dried during the primary drying period of the drying process.

Process for preparing a solid preparation of a penicillin derivative

Pharmaceutical compositions with controlled rates of gastro-intestinal absorption are prepared by dissolution or suspension of the therapeutically active agent in an absorption depressive agent selected from the group consisting of unsaturated aliphatic alcohols or their esters, unsaturated aliphatic ethers, unsaturated aliphatic acids or their salts, their esters or their amides and natural occurring oils containing more than 35% by weight of any of the above-mentioned substances, said absorption depressive materials having 12 - 22 carbon atoms in their unsaturated aliphatic hydrocarbon chains and being liquid at the normal temperature.

Pharmaceutical compositions having controlled rate of gastro-intestinal

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Ibaraki, Japan

Tadao Maeda