Formulation and Evaluation of Letrozole Loaded Hydrogels for Targeted Drug Release

Abstract

Hydrogels are three-dimensional, hydrophilic polymeric networks capable of absorbing significant amounts of water or biological fluids. Their high-water content, porosity, and soft, tissue-like consistency make them particularly suitable for topical drug delivery, offering enhanced patient comfort, sustained release, and reduced systemic side effects. The present study focuses on the formulation and evaluation of Letrozole-loaded hydrogel systems designed for localized delivery in hormone-responsive breast cancer treatment. Letrozole, a non-steroidal aromatase inhibitor, is typically administered orally, where it can lead to GIT discomfort and systemic toxicity. To address these limitations, a topical hydrogel formulation was developed using biocompatible gelling agents such as Carbopol 940 and PVA. FTIR analysis confirmed drug-excipient compatibility, preserving Letrozole’s structural integrity within the hydrogel matrix. Five hydrogel batches were prepared and assessed for physical characteristics, pH, viscosity, spreadability, drug content, and skin compatibility.  Among the formulations, F2 demonstrated optimal properties with a skin-friendly pH, good spreadability, and no signs of irritation, indicating its suitability for topical administration. The study highlights the potential of hydrogel-based Letrozole delivery as an effective, patient-friendly alternative to oral administration, supporting targeted drug release with minimal systemic exposure.