PROBLEM TO BE SOLVED: To provide a tenofovir disoproxil in a crystalline form C being tenofovir (9-[2-(R) phosphono methoxy) propyl] adenine represented by a formula (I) and having oral activity strong against human immunodeficiency virus (HIV) infection without substantially including impurities.SOLUTION: The tenofovir disoproxil in a crystalline form C, represented by a formula (I) has a XRPD pattern including peaks at 6.8, 23.2, 25.5 and 31.7°, 2&thetas；±0.2° and 2&thetas；. The method for manufacturing the tenofovir disoproxil in the crystalline form C or the salt thereof comprises: adding a solution including a tenofovir disoproxil and an organic solvent to salt saturated water； cooling the solution to a temperature less than 0°C to precipitate the tenofovir disoproxil in the crystalline form C； and optionally converting the tenofovir disoproxil in the crystalline form C into the salt of the tenofovir disoproxil in the crystalline form C.【課題】実質的に不純物を含まない、ヒト免疫不全ウィルス（ＨＩＶ）感染に対して強い活性を有する式（Ｉ）で表されるテノホビル（９－［２－（Ｒ）ホスホノメトキシ）プロピル］アデニン）の経口的に活性のある結晶性テノホビルジソプロキシル形態Ｃの提供。【解決手段】6.8、23.2、25.5及び31.7°2θ±0.2°2θにピークを含むXRPDパターンを有する、式（Ｉ）のテノホビルジソプロキシルの結晶、形態C。テノホビルジソプロキシル及び有機溶媒を含む溶液を塩飽和水に添加すること、該溶液を０℃未満の温度まで冷却し、それによって結晶形態Ｃのテノホビルジソプロキシルが沈殿すること、及び任意に該結晶形態Ｃのテノホビルジソプロキシルを結晶形態Ｃのテノホビルジソプロキシルの塩に変換することを含む結晶形態Ｃのテノホビルジソプロキシル又はその塩の製造方法。【選択図】なし
