Medical Developments International Limited announced that it has received correspondence from the USA Food & Drug Administration ("FDA") in relation to its Investigative New Drug ("IND") application to have Penthrox approved for sale in the United States of America. The FDA require MVP to identify an appropriate patient population for its suggested Phase I Study for whom the risk/benefit of Penthrox would be reasonable. In MVP's IND application, MVP suggested that the appropriate population would be Healthy Volunteers excluding patients who had previously developed hepatoxicity after administration of either methoxyflurane or halothane. The FDA has advised that it does not consider this population exclusion to be adequate. MVP believes it can identify an appropriate patient population and satisfy the FDA's concern. The FDA requested additional information and justification for the rare occurrence of idiosyncratic hepatoxicity. MVP believes it will be able to illustrate satisfactorily to the FDA the rare occurrence of idiosyncratic hepatoxicity and the acceptability of this risk in terms of the overall benefit of Penthrox compared with dangerous opioid alternatives. The FDA has asked for clarification around a chloroform impurity which is a process element in the manufacturing of methoxyflurane. MVP's new manufacturing technology meets the globally accepted standard for chloroform and MVP believe it can comply with the FDA's acceptable limits. The FDA raised questions about the "Instructions For Use" material for the Penthrox device (whistle). MVP believes it can satisfy the FDA in this regard. The FDA requires additional information about the variability of concentrations of the administration of methoxyflurane from closing the dilutor hole in the whistle. The FDA questioned the amount/volume of methoxyflurane captured in the activated carbon device (the AC Chamber device which fits on top of the whistle), which is used to scavenge the smell and the exhaled methoxyflurane from a patient's breath. The FDA has asked for additional testing to demonstrate the absorption capacity of the AC Chamber. MVP believes it can satisfy this request. The FDA queried the performance of the inbuilt valve system within the whistle and asked a number of questions around the performance characteristics of these valves. MVP believes it can satisfactorily respond to the FDA's questions.