Senju Pharmaceutical Co., Ltd.

Takeda Chemical Industries, Inc.

Hideo Terayama

Katsuhiro Inada

Shin-ichi Yasueda

Keiichi Matsuhisa

Jun Inoue

Yujiro Yamamoto

Hisayoshi Shimizu

Yasushi Morita

Mitsuaki Oshima

The aqueous suspension can be prepared by incorporating, in an aqueous suspension of a hardly soluble drug, a water-soluble polymer within the concentration range from the concentration at which the surface tension of the aqueous suspension of the drug begins to decrease up to the concentration at which the reduction in surface tension ceases. The resulting aqueous suspension shows ready redispersibility and will not undergo aggregation of dispersed particles or caking. Because of its good redispersibility, the suspension is useful as a parenteral preparation, eye drops, nasal drops, a preparation for oral administration, a lotion or the like.

Aqueous suspension with good redispersibility

Aqueous suspension preparations with excellent redispersibility

The conventional aqueous suspension of loteprednol etabonate is not easily amenable to production pH control and entails a pH depression on long-term storage, thus irritating the eye or the nasal mucosa on instillation. When a C2-7 aliphatic amino acid is added to an aqueous suspension of loteprednol etabonate for topical ophthalmic use, the suspension does not undergo pH depression even on prolonged storage, with the result that no irritable response is elicited in the eye or nasal mucosa.

Aqueous suspension of loteprednol etabonate

This invention relates to an aqueous preparation comprising a compound (A) represented by the formula: ##STR1## and at least one of cyclodextrins selected from .alpha.-cyclodextrin and dimethyl-.beta.-cyclodextrin; and a method of preparation thereof. According to the aqueous preparation of this invention, coexistence with at least one medicament selected from .alpha.-cyclodextrin and dimethyl-.beta.-cyclodextrin allows to enhance the solubility to water of compound (A) essential in this invention to such a concentration that makes an expected curative effect available and to inpart a desired stability to it. As a consequence, the aforesaid compound (A) can be utilized as a medicament for an aqueous preparation having anti-allergy action.

Aqueous preparation and method of preparation thereof

The compounds represented by the general formula ##STR1## wherein R is an alkyl group having 1-10 carbon atoms are novel compounds which have not been reported in the literature. Since they have excellent affinities for tissues with particular high corneal permeability and show anticataract activity at low concentration, the compounds are of value as prophylactic and therapeutic agents for cataracts.

1-hydroxy-oxo-5H-pyrido(3,2-a)phenoxazine-3-carboxylic acid esters

In the aqueous liquid preparation of this invention, which comprises a compound of the formula; ##STR1## wherein R is an alkyl having 1-6 carbon atoms, and at least one species of the solubilizers selected from the group consisting of polyvinylpyrrolidone, cyclodextrin and caffeine, the solubility of the compound in water can be heightened and the aqueous liquid prepared thereby can afford a desired stability and mitigate eye-irritation or nose-irritation.

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Itami, Japan

Hideo Terayama