Tolerance of Cyto-selective Difluoroethane-based Cryotherapy

Overview

Cryotherapy is more and more used to improve skin appearance. Devices using difluoroethane, manufactured by CRYONOVE PHARMA, are already available on the local and international markets, e.g. CRYOBEAUTY MAINS and CRYOBEAUTY CORPS. However, the cryogenic gas (conventional cryotherapy - liquid nitrogen) creates a dermabrasion of the skin surface and person receiving this kind of treatment presents an impaired skin during a few days following the treatment as temporary damage of stratum corneum, erythema, scars, burns. Following the side effects occurring after conventional cryotherapy application, it seems interesting for the sponsor to select other sequences of a cryogenic spray (4 prototypes of devices) which could be used for lentigo treatment with a same benefit for the consumers without any safety outcomes. This study will assess the use of different prototypes with a sequence of application of cryogenic gas which reaches a higher temperature than those which used with the reference device, in order to increase the acceptability of the device. (CS4\_3) proof of concept, interventional, monocentric, aims to evaluate the tolerance of cryotherapy treatments applied on healthy skin on the back of the hands. The main objective of the study is to evaluate on phototype V and VI, the tolerance of 4 different conditions of cryotherapy treatments (4 prototypes) applied on healthy skin on the back of the hands.

Prototypes (812A-v1), (812C-v1), (812D-v1) and (812F-v1) will be applied on hands areas by the same order for all volunteers using a reposition mask. On each hand 2 devices will be attributed starting from the middle point of the hand toward to the lateral internal and lateral external edges of the hand. The distance between 2 treatment areas will be 2 cm. Each area will be treated 1 time during the study at D0. The treatment will starts from right hand with prototypes (812A-v1) and (812C-v1), then left hands with the prototypes (812D-v1) and (812F-v1) . Prior to any study device application, the dermatologist will assess the adverse events. The dermatologist will verify that the skin has not been treated by cosmetic products (no presence of cream that could interfere with the treatment) and is dry. The procedure will take place at the investigation site. An operator previously trained by the dermatologist will apply the study device to the patient's hand. Subjects will lie down and the device will be administered upside down. The prototypes will be applied 10 minutes apart so that pain can be measured without interference from application to application.