Patient description: The patient is a 60-year-old Spanish man presenting with shortness of breath about a day before. The symptoms began acutely and progressively worsened. He is a known case of COPD since 2 years ago. The spirometry revealed post-bronchodilator FEV1/FVC = 60% of predicted values. He smokes 20 cigarette per day. His past medical history is remarkable for BPH and he is using Flomax for that. His family history is positive for HTN in his brother. His medication includes Duo-Neb inhaled q4 hr PRN, Vit D3 1000 units per day and Flomax for his PBH. He is an obese man who is acutely ill but oriented and conscious. The vital signs are as bellow: BP: 135/80 RR: 25/min HR: 75 bpm BMI: 40 O2sat: 90%

Clinical trial eligibility criteria: eligible ages (years): 18.0-55.0,  Healthy Volunteers who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests (including a normal coagulation profile), ECGs, vital signs and spirometry Normal spirometry FEV1 (Forced Expiratory Volume in the first second)≥80% of predicted, FEV1/Forced Vital Capacity (FVC) ratio ≥70%) at screening Non-smokers for at least one year and with a smoking history of less than 5 pack-years [number of pack years = (number of cigarettes per day/20) x number of years smoked] Body weight of ≥50 kg and a body mass index BMI (body mass index) of 20 to 24.9 kg/m2 Height 170 to 195 cm  Significant history of or current cardiovascular, respiratory (eg asthma, chronic obstructive pulmonary disorder (COPD), bronchiectasis, active Tuberculosis [TB]), hepatic, renal, gastrointestinal, endocrine, hematological, autoimmune or neurological disorders capable of significantly altering the absorption, metabolism, or elimination of drugs; constituting a risk when taking the study treatment; or interfering with the interpretation of data Skin lesions in the area used for the dermal application such as dermographism, dermatitis or eczema Use of prescription or non-prescription drugs (except paracetamol), including vitamins, herbal and dietary supplements (including St John's Wort) within 7 days or 5 half-lives (whichever is longer) before the first dose of study medication, unless, in the opinion of the investigator, the medication will not interfere with the study procedures or compromise participant safety History of sensitivity to enrofloxacin, ciprofloxacin or any other fluoroquinolones, or a history of drug or other allergy that, in the opinion of the investigator, contraindicates their participation Where participation in the study would result in donation of blood or blood products in excess of 500 mL within 3 months The participant has participated in a clinical trial and has received an investigational product within the following time period before the first dosing day in the current study: 30 days, 5 half-lives or twice the duration of the biological effect of the investigational product (whichever is longer) Regular use of known drugs of abuse or a positive drugs of abuse test at screening, positive cotinine test at screening History of regular alcohol consumption within 6 months of the study defined as an average weekly intake of >21 units for males or >14 units for females. One unit is equivalent to 8 g of alcohol: a half-pint (~240 mL) of beer, 1 glass (125 mL) of wine or 1 (25 mL) measure of spirits Upper or lower respiratory tract infection 4 weeks prior to screening