A unique two-excipient heat stable tablet formulation of oral insulin: preliminary results

We report a novel formulation approach for development of a thermostable oral insulin tablet. Using freeze drying to form a heat stable tablet in a single-step process, we demonstrate hydroxypropyl beta cyclodextrin (HP-β-CD) encapsulated lipophilic ion-pair complex of insulin using bile salt achieves intestinal absorption and sustained glucose levels. The tablets produced using this simple approach with only two excipients offer protection from enzymatic and stomach acid degradation and facilitate insulin uptake, without any need for specialized drug manufacturing or enteric coating. Insulin in this innovative formulation is thermotolerant, capable of maintaining stability even under heat stress at 30-40°C/65-75% RH. The convenient presentation of insulin as a thermostable oral tablet presents a low-cost scalable manufacturing method that simplifies the logistics of storage, transport, and distribution in any setting, including areas where cold storage maybe limited or unavailable. Graphical Abstract Our unique formulation approach protects insulin from stomach and temperature induced degradation, improves intestinal permeability providing a sustained release of insulin for glycemic control. The freeze dried tablet product format is easily scalable and flexible, increasing accessibility across all populations.