The depth of topical lidocaine penetration is time-dependent (for the amount of time it is on the skin).
In one study they found that with topical lidocaine placed on the skin for 90 minutes, the mean maximum depth was 5mm, and lasted ~240 minutes.
The depth of epidermis, dermis, and hypodermis vary depending on which part of the body. Could you be more specific as to which part of the body, and for how long(the cream would be on for)?
References: -Aesthetic Surgery Journal 2015, Vol 35(8) 1007–1013© 2015 The American Society for Aesthetic Plastic Surgery, Inc. DOI: 10.1093/asj/sjv079 www.aestheticsurgeryjournal.com