The main objective of the study is to determine the safety and tolerability of repeated application of PSD502 to the glans penis in healthy male volunteers

This is a phase I, double-blind, stratified, parallel group, placebo-controlled repeat dose study in a minimum of 8 circumcised and 8 uncircumcised healthy male volunteers. Subjects will attend 2 study visits, of which 1 will be a Screening Visit (Visit 1) and the other, a consecutive 21-day treatment visit (Visit 2; Days 1-21) which commences no more than 14 days after the Screening visit. Subjects will reside in the phase I unit throughout the treatment period. The duration of each subject's participation in the study will be up to 5 weeks.

Subjects are stratified based on whether they are circumcised or uncircumcised and within each stratified group subjects are randomized to PSD502 (lidocaine prilocaine spray) or placebo in a 3:1 ratio.

Procedures during the 21 day treatment period include: visual examination of the glans penis, blood sample collection for pharmacokinetic analysis of lidocaine and prilocaine, swabbing of the glans penis for residual PSD502, vital signs and 12-lead ECG, adverse event enquiries and collection of concomitant medications. Subjects are discharged from the clinic on Day 21 following a safety evaluation.

Inclusion Criteria:

• Willing and able to provide written informed consent
• Male, aged 18 years and over
• In generally good health in the opinion of the Investigator
• Willing and able to comply with all study procedures in the opinion of the Investigator

Exclusion Criteria:

• History of a significant medical condition that would preclude further study participation, in the opinion of the Investigator.
• Currently taking, or has taken within the 2 weeks prior to the Screening Visit, any concomitant medication that could confound interpretation of the safety data PSD502
• Suffering from an STD, or is positive for hepatitis B, hepatitis C, or HIV infection.
• Safety testing abnormalities at the Screening Visit, in particular liver function tests, that are indicative of a medical condition and that would preclude further participation, in the opinion of the Investigator.
• Significant abnormality of the glans penis that would preclude interpretation of the examination of the glans, or that could be worsened by use of PSD502.
• History of alcohol or drug abuse within 1 year prior to the Screening visit.
• Known drug sensitivity to amide-type local anesthetics.
• Use of an investigational (non-registered drug within 30 days of the Screening Visit.
• Unlikely to understand or be able to comply with study procedures, for any reason, in the opinion of the Investigator.
• History of Glucose-6-Phosphate Dehydrogenase (G-6-PD)deficiency or use of medications that would increase susceptibility to methemoglobinemia (e.g. anti-malarial agents).
• Use of class 1 (e.g. mexiletine, tocainide) and III (e.g. amiodarone, sotaolol)anti-arrhythmic drugs.