ALKYLGLYCOSIDES ENHANCE SYSTEMIC ABSORPTION OF INSULIN APPLIED TOPICALLY TO THE RAT EYE

A series of alkylglycosides with various alkyl chain lengths and carbo hydrate residues were tested for their ability to enhance systemic abs orption of insulin after topical ocular delivery in anesthetized rats. Several reagents, including tetradecyl-, tridecyl- and dodecylmaltosi de and dodecylsucrose, were potent stimulators of insulin absorption w hen used at concentrations as low as 0.125%. Other alkylglycosides suc h as decylsucrose, decylmaltoside, nonylglucoside, octylmaltoside, hep tylglucoside and hexylglucoside were less potent or ineffective as abs orption-enhancing reagents. By comparison, the bile salt sodium glycoc holate was effective only when used at concentrations of 0.5% or great er. All of the reagents were effective only when used at concentration s above their critical micelle concentration and the most hydrophobic alkylglycoside reagents were the most efficacious at promoting systemi c insulin absorption. The possible utilization of eyedrops containing insulin plus an absorption-enhancing alkylglycoside reagent in humans is discussed.