A sustained-release preparation which comprises a physiologically active peptide of general formula ##STR1## wherein X represents an acyl group; R.sub.1, R.sub.2 and R.sub.4 each represents an aromatic cyclic group; R.sub.3 represents a D-amino acid residue or a group of the formula ##STR2## wherein R.sub.3 ' is a heterocyclic group; R.sub.5 represents a group of the formula --(CH.sub.2).sub.n --R.sub.5 ' wherein n is 2 or 3, and R.sub.5 ' is an amino group which may optionally be substituted, an aromatic cyclic group or an O-glycosyl group; R.sub.6 represents a group of the formula --(CH.sub.2).sub.n --R.sub.6 ' wherein n is 2 or 3, and R.sub.6 ' is an amino group which may optionally be substituted; R.sub.7 represents a D-amino acid residue or an azaglycyl residue; and Q represents hydrogen or a lower alkyl group, or a salt thereof and a biodegradable polymer having a terminal carboxyl group. The sustained-release preparation shows a constant release of the peptide over a long time and is substantially free from an initial burst.
一种缓释制剂,包括一种具有通式##STR1##的生理活性肽,其中X表示酰基;R.sub.1,R.sub.2和R.sub.4各自表示芳香环基;R.sub.3表示D-
氨基酸残基或公式##STR2##的基团,其中R.sub.3'是杂环基团;R.sub.5表示公式--(CH.sub.2).sub.n--R.sub.5'的基团,其中n为2或3,R.sub.5'是
氨基基团,可以选择性地被取代,芳香环基或O-糖基;R.sub.6表示公式--(CH.sub.2).sub.n--R.sub.6'的基团,其中n为2或3,R.sub.6'是
氨基基团,可以选择性地被取代;R.sub.7表示D-
氨基酸残基或氮杂甘
氨酰残基;Q表示氢或低碳基,或其盐和具有末端羧基的可
生物降解聚合物。该缓释制剂显示出肽长时间的恒定释放,且基本上没有初始突发释放。