International Journal of Environmental Sciences ISSN: 2229 7359 Vol. 11 No. 18s, 2025 https://www.theaspd.com/ijes.php 2378 Design, Formulation, And Evaluation Of A Herbal Nanoemulsion-Based Topical Gel Containing Neem (Azadirachta Indica) And Vitamin E For Targeted Acne Treatment And Skin Inflammation Control Arpan Dutta 1 , Arnab Sarkar 2 , Priyanshi Goyal 3 , Mandava Mahima swaroopa 4 , Akash Verma 5 , Tanmay Ghosh 6 , Ankur Patel 7 , Udaybhan Yadav 8 , Madhu. C. Divakar *9 1 Research Assistant, Drug Chemistry Research Centre, Indore, Madhya Pradesh, India 2 Assistant Professor , Department of Pharmacognosy, Global College of Pharmaceutical Technology, Bhatjangla More, Krishnanagar, India 3 Assistant Professor, School of Pharmacy, Mangalayatan University, Beswan, Uttar Pradesh , India 4 Assistant Professor, Department of Pharmacy Practice, Koneru Lakshmaiah Education Foundation, Greenfileds, Vaddeswaram, Guntur, Andhra Pradesh, 522302, India 5 Teerthanker Mahaveer College of Pharmacy, Teerthanker Mahaveer University, Moradabad-244001, U.P., India 6 Assistant Professor, Department of Microbiology, Dinabandhu Andrews College, Baishnabghata, South 24 Parganas, Kolkata, West Bengal, India 7 Assistant Professor, Department of Pharmaceutics, 244, Sardar Patel College of Pharmacy,Vidyanagar - Vadtal Road, Bakrol Dist & Ta-Anand, State Gujarat, India 8 I/c Head and Assistant Professor, Department of Botany, Thakur Shyamnarayan Degree College, University of Mumbai, Mumbai, Maharashtra, India 9 Professor, Department of Pharmacognosy and Phytochemistry , PPG College of Pharmacy, Saravanampatti, Coimbatore, Tamilnadu, India Abstract Background: Acne vulgaris and associated skin inflammation are widespread dermatological conditions with multifactorial etiology, including bacterial infection, inflammation, and oxidative stress. Conventional treatments often present limitations such as irritation, microbial resistance, and poor patient compliance. Plant-based therapeutics, especially neem (Azadirachta indica) and vitamin E, have shown promise due to their antimicrobial and anti-inflammatory properties. However, poor solubility and limited skin penetration reduce their clinical efficacy. Objective: To design, formulate, and evaluate a nanoemulsion-based herbal gel incorporating neem extract and vitamin E for enhanced dermal delivery, targeting acne and skin inflammation. Methods: Neem extract was obtained via Soxhlet extraction and incorporated with vitamin E into a nanoemulsion system using isopropyl myristate as the oil phase and Tween 80/PEG-400 as surfactant/co-surfactant. Pseudo-ternary phase diagrams were constructed for optimization. The nanoemulsion was converted into a nanoemulgel using Carbopol 940. Formulations were evaluated for droplet size, zeta potential, viscosity, spreadability, drug release, antimicrobial and anti- inflammatory activities, and skin irritation in Wistar rats. Results: The optimized nanoemulsion had a droplet size of 142.6 ± 3.2 nm, PDI of 0.178, and zeta potential of –29.4 mV. The nanoemulgel exhibited good viscosity, spreadability, and homogeneity. In vitro drug release was 82.5% over 8 hours, fitting the Korsmeyer–Peppas model (R² = 0.961). The formulation showed significant antibacterial activity against P. acnes (21.4 mm) and S. aureus (19.7 mm), and inhibited albumin denaturation (78.4%) and hemolysis (72.6%). No signs of erythema or edema were observed in skin irritation tests. Conclusion: The developed herbal nanoemulgel demonstrated excellent physicochemical characteristics, sustained drug release, and promising antimicrobial and anti-inflammatory effects without skin irritation. It offers a potent and safe