A functionalized starch having a single helix V structure and having a degree of substitution of at least 0.25, and within the helix V structure of the functionalized starch forming an inclusion complex with the functionalized starch and having the single helix V structure; The powder composition comprising the bioactive agent contained in is described. Also described is a functionalized starch having a single helix V structure and a degree of substitution of at least 0.25, a method for its preparation, and a method for its use to produce a powder composition.一重らせんV構造を有し、少なくとも0.25の置換度を有する官能化デンプン、および前記官能化デンプンと包接錯体を形成し、前記一重らせんV構造を有する官能化デンプンの前記らせんV構造内に含まれる生物活性剤からなる粉末組成物について記載する。また、一重らせんV構造を有し、少なくとも0.25の置換度を有する官能化デンプン、その調製方法、および粉末組成物を製造するためのその使用方法について記載する。