Development, Characterization, and Clinical Evaluation of a 6% Nitroglycerin–Aloe Vera Transdermal Gel for Stable Angina Management

Muhammad Omer Iqbal,1,2 Kashaf Khan Anjum Bhutta,2 Imran Ahmad Khan,3 Inam Ur Rehman,4 Maliha Khalid Khan,2 Yuchao Gu,1 Jin Chen,1 Xiao Wu5 1College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, Shandong, 266042, People’s Republic of China; 2Ali-Ul-Murtaza, Department of Rehabilitation Sciences, Muhammad Institute of Medical and Allied Sciences, Multan, Punjab, 60000, Pakistan; 3Department of Pharmacy, MNS University of Agriculture, Multan, Punjab, 60000, Pakistan; 4Department of Intensive Care Unit, CPE Institute of Cardiology, Multan, Punjab, 60000, Pakistan; 5Qingdao Central Hospital, University of Health and Rehabilitation Sciences (Qingdao Central Medical Group), Qingdao, Shandong, 266042, People’s Republic of ChinaCorrespondence: Imran Ahmad Khan, Email imranahmadkhandurrani@gmail.com Xiao Wu, Email wuxiao990222@163.comPurpose: This study aimed to develop, characterize, and clinically evaluate a novel 6% nitroglycerin (NTG) Aloe vera gel formulation as a transdermal alternative to conventional sublingual NTG therapy in patients with stable angina pectoris.Patients and Methods: A randomized, parallel-group, double-blind clinical trial was conducted involving 150 patients with stable angina, allocated to receive either 6% NTG-Aloe vera gel or standard sublingual NTG tablets (0.6mg). The gel was assessed for physicochemical parameters, FTIR compatibility, stability under ICH guidelines, and in vitro drug release kinetics. Dermatological safety was evaluated via skin irritation testing. Clinical efficacy was determined by Numeric Pain Rating Scale (NPRS), chest tightness scores, Seattle Angina Questionnaire (SAQ), and vital parameters, including blood pressure and oxygen saturation.Results: The NTG Aloe vera gel demonstrated desirable physicochemical properties, sustained zero-order drug release, and excellent stability with no significant degradation. Clinical data revealed that the gel provided gradual, sustained pain and chest tightness relief, superior SAQ scores (p< 0.001), and improved tolerability compared to sublingual NTG. Importantly, the gel induced a controlled hypotensive response without abrupt cardiovascular changes, indicating enhanced safety. No dermatological adverse effects were reported.Conclusion: This pilot study showed 6% NTG-Aloe vera gel offers a stable, effective, and patient-friendly transdermal delivery system for angina management, meriting further large-scale and long-term evaluations.Registration: Clinical Trial Registry-India (CTRI/2024/11/076947). Keywords: nitroglycerin, aloe vera, angina pectoris, transdermal drug delivery systems, pharmaceutical preparations