Effectiveness of liposomal system of delivery of hydrophobic antineoplastic thiosens photosensitizer

The implementation of liposome delivery systems ensures the intravenous introduction of hydrophobic photosensitizers used in the treatment of tumors by the photodynamic therapy method with their preservation in a therapeutically effective nonaggregated form and high accumulation selectivity in the tumor. Phthalocyanines are one of the fastest growing classes of antineoplastic photosensitizers, most of which are hydrophobic compounds. In this study the authors have developed the unique composition and technology of preparing the lyophilized liposomal formulation of infrared photosensitizer: aluminum hydroxide tetra-3-phenylthiophtalocyanine (Thiosens). At the stage of biological experiments on model mouse tumors, the preservation of high accumulation selectivity in the tumor (selectivity index is higher than 4) and antineoplastic effectiveness (inhibition of tumor growth is from 70 to 94%) were found during the transition from the previously studied model dosage form to the created lyophilized liposomal one. To estimate chemical and pharmaceutical criteria and the photodynamic efficiency of the photosensitizer on a number of transplanted mice tumor models in vivo, we have conducted a preclinical study which has demonstrated the stability of antitumor activity and quality consistency of the developed dosage form for one and a half years.