Transdermal delivery of insulin with bioceramic composite microneedles fabricated by gelatin and hydroxyapatite.

The organic-inorganic bioceramic composite microneedles (MNs) were prepared from hydroxyapatite (Hap) and gelatin (Gel) via a template method. The resultant hydroxyapatite and gelatin composite MNs exhibited low cytotoxicity and excellent mechanical properties. After transdermal administration to the diabetic rats, the insulin could be released from bioceramic composite MNs. An obvious and effective hypoglycemic effect could be obtained compared with that of subcutaneous injection route. This work suggests that bioceramic composite MNs containing of insulin have a potential application in diabetes treatment via transdermal ingestion.