Pyramidal microneedles with enhanced drug loading capacity and method for manufacturing

Abstract

The present invention provides a solution to increase the drug loading capacity and drug delivery precision of dissolving microneedles. These solutions include: (a) increasing the base of the microneedle cavities without substantially changing the microneedle's height and geometry, (b) use of drug suspension and sedimentation of drug by centrifugation, and (c) a specific centrifugation order for filling drug and matrix material. In the first preferred embodiment, a microneedle master mould comprising a plurality of pyramidal microneedles (), wherein each of the pyramidal microneedles further comprising a chamfered base () which extends to and adjoins with its neighbouring chamfered bases is provided. In the second preferred embodiment, a method of making dissolving microneedles is provided, comprising (a) providing a microneedle template comprising a plurality of pyramidal microneedle cavities, wherein each of the pyramidal microneedle cavities further comprising a chamfered base which extends to and adjoins with its neighbouring chamfered bases; (b) loading a drug suspension in the substrate cavity on the microneedle template; (c) centrifuging the microneedle template which is loaded with a drug suspension, (d) loading a matrix material solution in the substrate cavity on the microneedle template; (d) centrifuging the microneedle template loaded with the drug suspension and the matrix material solution; and (e) drying the centrifuged microneedle template in a controlled environment.