A Review: Topical Gels for Localized Drug Delivery

Abstract

Topical gels have revolutionized localized drug delivery, offering a non-invasive, patient-friendly approach to treat a wide array of conditions, including dermatological disorders, musculoskeletal pain, and infections. Their semi-solid nature, combined with excellent spreadability, cooling sensation, and controlled release properties, makes them a preferred choice in pharmaceutical and cosmetic applications. This review provides an in-depth exploration of topical gels, covering their types, formulation strategies, evaluation methods, regulatory frameworks, and recent innovations. Synthetic gelling agents like carbopol and natural alternatives like xanthan gum and aloe vera are discussed for their roles in enhancing drug permeation and skin compatibility. The growing demand for eco-friendly and herbal-based gels, driven by consumer preference for sustainable products, is also examined. Advanced technologies, such as thermoresponsive gels, bioadhesive systems, and nanotechnology-based formulations, are highlighted for their potential to improve efficacy and patient compliance. Comprehensive evaluation techniques, including pH analysis, viscosity measurement, in vitro drug release, and skin irritation tests, ensure product quality and safety. The review concludes with future prospects, emphasizing sustainable packaging, biodegradable polymers, AI-driven formulation design, and personalized therapies to address evolving healthcare needs. This paper aims to serve as a valuable resource for researchers, formulators, and healthcare professionals interested in advancing topical gel technology.

Introduction

Topical gels are semi-solid drug delivery systems designed for application on the skin or mucosal surfaces to treat local conditions or enhance skin health. Their non-greasy nature, ease of application, and fast drug release make them popular in pharmaceutical and cosmetic fields.

Key Highlights

???? 1. Formulation and Composition

• Made with water- or lipid-based polymers (e.g., carbopol, HPMC).

• Can deliver both hydrophilic and lipophilic drugs.

• Incorporate gelling agents, penetration enhancers, and sometimes natural extracts.

• Types include:

  • Hydrogels – water-based, cooling, ideal for wounds.

  • Organogels – lipid-based, good for deep penetration.

  • Emulgels – blend of gel + emulsion for dual-solubility drugs.

  • Thermoresponsive gels – transform from liquid to gel at body temperature.

  • Herbal gels – contain plant-based actives like neem, aloe vera.

  • Bioadhesive gels – adhere to skin/mucosa for prolonged effect.

???? 2. Therapeutic and Cosmetic Applications

• Antimicrobial treatment: e.g., clindamycin, ketoconazole.

• Pain management: NSAID gels like diclofenac for arthritis.

• Dermatological use: Treat acne, eczema, psoriasis.

• Cosmetic use: Anti-aging gels with vitamin C, peptides.

• Wound healing: Hydrogels with silver nanoparticles or growth factors.

• Benefit: Localized action minimizes systemic side effects.

???? 3. Market Trends & Demand

• Valued at $8.5 billion in 2024, with a projected 7.2% CAGR through 2032.

• Driven by:

  • Increase in skin disorders and aging population.

  • Growing cosmetic awareness.

  • Technological advances in nanogels and stimuli-responsive systems.

  • Demand for natural and sustainable products.

• Regions like North America and Asia-Pacific dominate the market.

???? 4. Role in Public Health & Pandemics

• Played a vital role during COVID-19 as antimicrobial gels.

• Used in infection control, especially where water is scarce.

• Benefits:

  • Easy self-administration

  • Suitable for vulnerable populations

  • Portable and fast-acting

• Emphasis on public education and proper application to maximize effectiveness.

???? 5. Regulatory and Safety Aspects

• Regulated by FDA, EMA, and WHO.

• Requirements include:

  • pH compatibility, stability testing, labeling

  • Preservatives to prevent microbial growth

  • Hypoallergenic formulations to avoid irritation

• Safety concerns include:

  • Skin irritation from excipients or preservatives

  • Risk of systemic absorption with potent drugs

???? 6. Innovations and Challenges

Innovations:

• Nanoparticles improve drug penetration and bioavailability.

• 3D printing enables personalized gel designs.

• Stimuli-responsive gels offer precise, targeted release.

• Herbal gels reduce reliance on synthetic ingredients.

Challenges:

• Limited drug penetration through the skin barrier

• Risk of instability, crystallization, or microbial contamination

• Packaging and storage requirements

• Regulatory hurdles for novel formulations

? 7. Advantages of Topical Gels

• Non-greasy and aesthetically pleasing

• Rapid absorption and localized effect

• High patient compliance and ease of use

• Compatible with various drug types

• Suitable for controlled and sustained drug release

• Generally cost-effective and stable

?? 8. Disadvantages

• Limited absorption for large or lipophilic drugs

• Can cause irritation or allergic reactions

• Short skin residence time unless bioadhesive

• Formulation complexity and risk of instability

• Inconsistent dosage if applied manually

• Less effective in very dry or thickened skin

Conclusion

Topical gels have emerged as a cornerstone of modern healthcare, offering targeted, non-invasive drug delivery with high efficacy and patient acceptability. Their versatility spans antimicrobial therapy, pain management, dermatological care, cosmetic applications, and wound healing, making them indispensable in clinical and self-care settings. Advances in polymer science, nanotechnology, bioadhesive systems, and herbal formulations have expanded their therapeutic and cosmetic potential, while rigorous evaluation ensures safety, stability, and performance. Regulatory frameworks provide a robust foundation for quality assurance, guiding the development and commercialization of innovative gels. Despite challenges like skin barrier penetration, stability issues, and environmental concerns, ongoing research is addressing these limitations through sustainable materials, smart delivery systems, and personalized therapies. The global topical gel market continues to grow, driven by rising health awareness, technological advancements, and consumer demand for eco-friendly products. Future innovations, including AI-driven design, IoT-enabled applicators, and microbiome-friendly formulations, promise to revolutionize topical gel technology, solidifying their role in global health and wellness. This review underscores the transformative potential of topical gels, offering a roadmap for researchers, formulators, and healthcare professionals to advance this dynamic field.

References

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Copyright

Copyright © 2025 Riya Teelante, Aishwarya Todkar, Nitin Gawai, Sakshi Gore, Hari Madake. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.