Development and Evaluation of a Transdermal Patch of Acorus calamus for the Management of Diabetic Neuropathy

Diabetic neuropathy is a chronic and progressive microvascular complication of diabetes mellitus, affecting up to 50% of diabetic patients. It is characterized by peripheral nerve damage resulting in sensory loss, pain, and motor deficits, severely affecting patients’ quality of life. Current pharmacological therapies are often limited by systemic toxicity, poor patient compliance, and variable efficacy. In this context, transdermal drug delivery systems (TDDS) offer an attractive alternative by providing controlled drug release, improved bioavailability, and avoidance of first-pass metabolism. Acorus calamus, also known as sweet flag, is an aromatic medicinal herb traditionally used in Ayurvedic and Chinese medicine for its neuroprotective, analgesic, anti-inflammatory, and antioxidant activities. Its major bioactive constituents, particularly β-asarone and eugenol, have shown promise in modulating oxidative stress and inflammatory pathways implicated in neuropathic pain. The present study aimed to formulate and evaluate a transdermal patch of Acorus calamus extract for the effective treatment of diabetic neuropathy. The hydroalcoholic extract of Acorus calamus rhizome was prepared by maceration and standardized using phytochemical analysis and HPLC profiling. The transdermal patches were developed using the solvent casting method with polymers such as HPMC (hydroxypropyl methylcellulose) and PVP (polyvinylpyrrolidone), along with suitable plasticizers like glycerin. The formulated patches were evaluated for physicochemical parameters including thickness, weight uniformity, folding endurance, tensile strength, surface pH, drug content uniformity, and moisture content. In conclusion, the Acorus calamus-based transdermal patch represents a promising phytopharmaceutical approach for the management of diabetic neuropathy with improved patient adherence and minimal side effects.