Large scale production of DC-Chol cationic liposomes by microfluidization

In this report, we describe the large scale production and testing of DC-Chol cationic liposomes by microfluidization. These liposomes are produced in a GMP acceptable manner to a 500 ml batch size and are shown to be sterile. Further, when stored at 4 degrees C, DC-Chol liposomes will retain their original size, remain suspended in solution, and retain activity for a period exceeding 1.5 years. In-process QA and QC procedures have identified problems in processing and methods to produce a final product of pharmaceutical quality have been developed to overcome these obstacles. Assays for product content (DC-Chol and DOPE assays), size, sterility, endotoxin determination, storage conditions and shelf life have been developed. Successful lots have been used in a human gene therapy clinical trial for cystic fibrosis at Oxford University as well as many pre-clinical experiments throughout the world. Implications for application to further gene therapy clinical trials as well as the development of liposome vector programs are discussed in detail. Copyright (C) 1996 Elsevier Science B.V.