HERBAL DRUG-LOADED TRANSDERMAL DRUG DELIVERY SYSTEMS: A NOVEL APPROACH IN PHARMACEUTICAL DOSAGE FORMS

Transdermal drug delivery systems (TDDS) are innovative pharmaceutical dosage forms designed to provide controlled and sustained release of drugs through the skin, offering benefits such as bypassing first-pass metabolism, reducing dosing frequency, and improving patient compliance.. In recent years, the integration of herbal bioactive compounds into TDDS has gained attention due to the increasing demand for natural, safe, and effective therapeutic approaches. Herbal constituents such as andrographolide, curcumin, capsaicin, caffeine, and aloe vera exhibit diverse pharmacological properties, including anti-inflammatory, anti-diabetic, antioxidant, analgesic, and wound-healing activities. Nevertheless, their clinical use is often hindered by challenges like limited skin permeability, low aqueous solubility, and physicochemical instability. Advances in formulation strategies—such as nanocarrier incorporation (liposomes, ethosomes, transfersomes), microneedle-assisted delivery, and penetration enhancers—have been effective in improving dermal absorption and bioavailability of these phytochemicals. Key evaluation parameters, including physicochemical profiling, mechanical strength, drug content uniformity, and in vitro permeation studies, are critical for ensuring safety and therapeutic efficacy. This review highlights current advancements, formulation techniques, evaluation methodologies, challenges, and future directions for herbal drug-loaded TDDS, underscoring their potential to merge traditional herbal medicine with modern drug delivery innovations for optimized patient care.