Microneedle Array Mold Segmentation for Drug Amount Precision
Solution Overview
Problem
Existing microneedle arrays face challenges in precision control of drug amount and dimensional accuracy, leading to variations in drug delivery and increased production costs due to labor-intensive inspection processes.
Innovation Solution
A method involving the injection of a predetermined amount of raw material liquid into cone-shaped recesses of a mold, followed by a tip forming step where insoluble or sparingly soluble frustum-shaped protrusions are used to fix cone-shaped tips, ensuring precise control and easy release into the skin, along with a mold release step to form a microneedle array with cone-shaped tips at a predetermined height.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional microneedle production methods are used, then microneedles can be formed on a sheet, but the amount of drug contained in one microneedle cannot be managed with high precision, leading to variations in drug delivery
Solution Approach 1:
The microneedle array is divided into multiple individual microneedles, each formed in a separate mold cavity. This segmentation allows independent control of drug amount in each microneedle during the molding process, enabling precise management of drug containment and uniform delivery across the array.
Solution Approach 2:
The drug is pre-mixed with the resin material before injection into the mold. This preliminary action ensures uniform drug distribution within the resin, allowing precise control of drug amount in each microneedle from the formation stage, eliminating variations in drug delivery.
2Manufacturing precision
If conventional microneedle production methods are used, then microneedles can be formed, but dimensional error of the microneedle shape is not reduced, affecting effective perforation of the stratum corneum
Solution Approach 1:
The mold is divided into multiple independent cavities, each forming a single microneedle. This segmentation allows precise control of the forming conditions for each microneedle, reducing dimensional errors and ensuring consistent shape that effectively perforates the stratum corneum.
Solution Approach 2:
The injection molding parameters (temperature, pressure, injection rate) are optimized and controlled within specific ranges to minimize dimensional errors in the microneedle shape. By changing and controlling these parameters, the microneedles achieve the precise dimensions needed for effective skin perforation.
3Measurement precision
If conventional microneedle production methods are used, then microneedles can be produced, but inspection and quantification of drug amount requires careful work, increasing production cost
Solution Approach 1:
The microneedles are formed with self-contained drug reservoirs during the molding process itself. The mold design and injection process automatically ensure proper drug containment, eliminating the need for separate, labor-intensive inspection and quantification steps, thereby reducing production cost.
Solution Approach 2:
The manual inspection process is replaced by the automated injection molding process that inherently controls drug amount. The mechanical injection system precisely delivers the correct amount of drug-resin mixture to each cavity, substituting labor-intensive measurement with automated process control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for high-precision control of the drug amount administered, reduces dimensional errors, and lowers production costs by simplifying the inspection process and ensuring consistent drug delivery.
Implementation Method 1
drying the raw material liquid in the plurality of cone-shaped recesses thereby fixing a plurality of cone-shaped tips that are dissolvable in an inner part of skin to a tip surface of each of the plurality of frustum-shaped protrusions or columnar protrusions
Data Source
AI summary
Provided is an inexpensive microneedle array with little dimensional error that can control, with high precision, the amount of a predetermined component to be introduced to the inner part of the skin, and a production method for this microneedle array. A foundation that is insoluble or sparingly soluble in inner part of the skin is overlaid on a mold. A plurality of frustum-shaped protrusions, which are insoluble or sparingly soluble in the raw material liquid, provided on a first main surface of the foundation are fit into a plurality of cone-shaped recesses. The raw material liquid in the plurality of cone-shaped recesses dries and, as a result, a plurality of microneedles, which are dissolvable in the inner part of the skin, are fixed to tip surfaces of the plurality of frustum-shaped protrusions.