Safety and Performance Evaluation of pH‐Responsive Polymer Microencapsulation in Menstrual Hygiene Products

ABSTRACT Effective menstrual hygiene management (MHM) is crucial for adolescent girls and women, yet conventional sanitary napkins present health, environmental, and cost‐related challenges. This study reports the synthesis of pH‐responsive superabsorbent polymers (SAPs) via free radical copolymerization of selected monomers for seven formulations followed by microencapsulation with n‐eicosane (mSAPs) for application in hygienic textiles. The polymers were characterized using FT‐IR spectroscopy, thermogravimetric analysis (TGA), and particle size analysis. All formulations (SAP/mSAP‐1C to SAP/mSAP‐7C) were evaluated for free swell capacity (FSC), absorption under load (AUL), wet back, wicking height, pH responsiveness, and reusability. The optimized mSAP formulation exhibited excellent swelling capacity (FSC: 106.55 g/g) and minimal wet back (0.26 g), outperforming commercial products in absorbency and comfort. AUL values exceeded 98%, confirming strong gel stability. Effluent analysis (hardness, alkalinity, chloride, COD, BOD) confirmed acceptable discharge quality. Safety assessments—and HRIPT (sample size n = 105)—showed no skin irritation or sensitization in normal and sensitive skin. Although absorption decreased in saline solutions due to ionic charge screening, the prepared SAPs and mSAPs demonstrated significant potential for hygienic applications. Despite their promising performance, the non‐biodegradable nature of these polymers highlights the need for eco‐friendly modifications and sustainable disposal strategies.