Clove-based gels and nanoformulations show promise against gum disease

Clove, the dried flower bud long associated with toothache remedies, is being re-examined by pharmaceutical scientists as a candidate for far more sophisticated periodontal treatment. A review published in Clinical Phytoscience by Himanshu Yadav, Ritesh Kumar Tiwari and Shashi Verma examines novel drug delivery systems built around clove oil and its principal active compound, eugenol, and evaluates their therapeutic potential for periodontal diseases, the inflammatory conditions that destroy the tissues supporting the teeth. The authors conclude that clove-derived formulations show strong potential as adjunct therapeutic agents, while stressing that further clinical research is necessary before such products can claim an established place in dentistry.

Periodontal disease is a serious global public health problem affecting people of all backgrounds. It encompasses inflammatory conditions such as gingivitis and periodontitis, driven largely by plaque accumulation in the periodontal pockets. In periodontitis, the pathophysiology involves a complex interaction between a dysbiotic microbial biofilm and the host immune-inflammatory response. Excess reactive oxygen species produced during immune activation generate oxidative stress, which plays a critical role in tissue damage and disease progression, propagating the destruction of connective tissue and alveolar bone through inflammatory mediators and matrix-degrading enzymes.

The rationale for clove rests on its chemistry. Clove flower bud essential oil contains 75 to 88 percent eugenol, a phenolic compound with documented antimicrobial, anti-inflammatory and analgesic qualities. Eugenol’s antibacterial activity appears to centre on disruption of the bacterial cell membrane, increasing permeability and leakage of ions and intracellular contents, alongside inhibition of key microbial enzymes and possible interference with bacterial DNA replication. Its antioxidant and anti-biofilm activities may reduce oxidative stress and inhibit biofilm formation on tooth and implant surfaces. On the inflammatory side, eugenol has been shown to inhibit cyclooxygenase-2 and lipoxygenase enzymes and to decrease production of prostaglandin E2, NF-κB, IL-6 and TNF-α, mediators central to periodontal tissue destruction.

The review’s central argument is that conventional delivery of clove actives has been hampered by poor water solubility, chemical instability, rapid metabolism and non-specific tissue distribution. Novel drug delivery systems, including nanoemulsions, nanoemulgels, nanocapsules, nanofibers and films, are designed to overcome exactly these setbacks. Nanoformulations improve the solubility of lipophilic drugs such as eugenol by presenting a small particle size and therefore a higher surface area for solubility and biological interactions, improving permeation and bioavailability at biological barriers such as the mucosal layers encountered in periodontitis. Colloidal stability also shields eugenol from environmental and enzymatic degradation.

According to the review, clove-based formulations show favourable physicochemical stability and patient acceptability, reduce inflammatory markers including COX-2, TNF-α and IL-6, and display significant antimicrobial activity against important periodontal pathogens such as Porphyromonas gingivalis and Prevotella intermedia. Gels and films offer localized, sustained release, which the authors argue enhances therapeutic outcomes and reduces systemic side effects. Specific platforms described include clove oil nanoemulsions and eugenol nanoemulgels using surfactants such as Tween-80 and polymers such as Carbopol for sustained release and penetration into gingival tissues, electrospun nanofibers acting as fast-dissolving matrices, and polycaprolactone nanocapsules providing biphasic release for localized anti-inflammatory effects without systemic toxicity in experimental settings.

The evidence base behind these claims is uneven, and the authors are explicit about this. In vitro assays demonstrate strong antimicrobial activity of clove oil against periodontal pathogens including Porphyromonas gingivalis, Prevotella intermedia and Aggregatibacter actinomycetemcomitans, often synergizing with antibiotics to enhance killing rates, and formulations such as clove oil dental gels and nanogels show controlled release and inhibition of biofilm-forming bacteria in laboratory tests. Animal studies of clove oil or eugenol gels and nanoformulations in periodontitis models have reported decreased pro-inflammatory cytokine levels, gingival inflammation and alveolar bone loss. These preclinical data provide proof of concept, the review notes, but do not in isolation ensure safety and efficacy in humans.

Human evidence remains comparatively thin. A mouth rinse combining clove oil, tea tree oil and basil reduced plaque, gingivitis and bacterial load in a comparative trial, performing comparably to chlorhexidine as an adjunct to mechanical therapy. Small trials and pilot studies have reported improvements in gingival index, plaque scores and patient-reported pain relief. However, the review states that large-scale clinical trials are limited in number, that most evidence originates from smaller studies, and that the overall clinical evidence is at best moderate in quality, with larger, longer-term randomized controlled trials required to establish a strong clinical role for clove in periodontology.

Safety considerations also temper enthusiasm. Eugenol is a primary irritant and can irritate skin, mucosa and respiratory membranes; in dental applications it can induce allergic contact dermatitis and contact gingivitis, with irritative effects that are dose-related. There is no standard defined maximum dosage limit for eugenol in periodontal pockets, and high dosages or accidental ingestion can lead to severe systemic toxicity including hepatic and renal failure. The review notes that eugenol causes more irritation but less systemic toxicity than chlorhexidine and doxycycline gels in comparative testing, and that topical formulations therefore aim to reduce concentration while preserving antimicrobial and analgesic action. Standardization of eugenol content, using validated analytical methods such as HPLC and ATR-FTIR spectroscopy, is highlighted as essential for maintaining uniformity, safety and efficacy across formulations.

The review also situates clove formulations within a broader commercial and technological landscape. The periodontal therapeutics market, which includes sophisticated delivery devices, was worth USD 872.8 million in 2023 and is estimated to reach between USD 1.41 and 1.67 billion during 2030 and 2032, growing at 6 to 7.6 percent annually, driven by rising periodontitis incidence, minimally invasive dentistry and acceptance of nanotechnology, led by the Asia-Pacific region. Emerging delivery trends include in-situ gels that transition from liquid to gel within periodontal pockets, microsponges achieving diffusion-controlled release for up to 5 to 7 days, and depot systems sustaining drug release beyond 72 hours to overcome salivary clearance.

Ultimately, the review presents clove-based formulations as promising but still investigational adjuncts to periodontal therapy. The authors identify key knowledge gaps: a need for randomized clinical trials comparing clove formulations with traditional adjunctive therapies using standardized clinical and microbiological parameters and long-term follow-up; studies of formulation stability, biocompatibility and interactions with antibiotics; assessment of patient-reported outcomes such as pain relief and adherence; and mechanistic work on how eugenol modulates periodontal immune pathways. They also acknowledge limitations of their own review, including heterogeneous study designs, small sample sizes, limited safety reporting and possible publication bias. Until long-term human data become available, the review concludes, the therapeutic effects of novel clove formulations should be regarded as promising yet still investigational, most likely to be found in complementary and supportive roles rather than as standalone periodontal therapies.

Subject of Research: A review of novel clove and eugenol drug delivery formulations for periodontal disease therapy.

Article Title: From tradition to therapy: novel clove formulations in periodontal therapy

Article References: Yadav, H., Tiwari, R. K., & Verma, S. (2026). From tradition to therapy: novel clove formulations in periodontal therapy. Clinical Phytoscience, 12(1), Article 11. https://doi.org/10.1186/s40816-026-00427-3

Image Credits: AI Generated

DOI: 10.1186/s40816-026-00427-3

Keywords: clove, eugenol, periodontitis, nanoformulations, drug delivery, antimicrobial, anti-inflammatory, Syzygium aromaticum, oral health, systematic review, dental gels, preclinical evidence