Microcapsules and transdermal patch: a comparative approach for improved delivery of antidiabetic drug

Glibenclamide (GL)-loaded microcapsules (MC) and transdermal patches (TDP) were formulated and in vitro and in vivo parameters compared to find out the best route of drug administration. The formulation TDP1 having a drug-polymer ratio 1:1 showed comparatively higher GL release and better permeation across mice skin (p < 0.05). From the comparative study, it was concluded that the transdermal system of GL produced better improvement compared to oral microcapsule administration (p < 0.05). The transdermal system exhibited comparatively slow and continuous supply of GL at a desired rate to systemic circulation avoiding metabolism, which improved day-to-day glycemic control in diabetic subjects. Transdermal system of GL exhibited better control of hyperglycemia and prolonged plasma half-life by transdermal systems (9.6 +/- 1.2 h) in comparison with oral microcapsule (5.84 +/- 2.1 h), indicating that the drug, when administered by transdermal systems, will remain in the body for a longer period. From the glucose tolerance test, transdermal route effectively maintained the normoglycemic levels in contrast to the oral group (MC1), which produced remarkable hypoglycemia ranging from -12.6 +/- 2.1% to -18 +/- 2.3%. The significantly high (p < 0.05) area under the curve values observed with transdermal system (1,346.2 +/- 92.3 ng ml(-1) h(-1)) also indicate increased bioavailability of the drug from these systems compared to the oral route (829.8 +/- 76.4 ng ml(-1) h(-1)).