Angular Drug Particles Penetrate Skin Barrier
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Solution Overview
Problem
Current methods for transdermal drug delivery, such as microneedle arrays, face challenges in mass production, cost, and limited size, with the stratum corneum being a significant barrier to drug absorption, and there is a need for more efficient and cost-effective solutions for delivering drugs through the skin or cornea.
Innovation Solution
The use of rigid, irregular, angular particles that are soluble or biodegradable, with sharp edges capable of penetrating the skin or cornea, combined with excipients to enhance physical and chemical properties, allowing for deeper absorption and easier manufacturing, and application via patches or devices with blunt-tipped projections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional microneedle arrays are used for transdermal delivery, then drug delivery through the stratum corneum is achieved, but the manufacturing process is slow and expensive with limited array size
Solution Approach 1:
The invention divides the microneedle array into individual microneedle units that can be separately manufactured and then assembled. Each microneedle is formed in a mold cavity, allowing independent production and quality control, which simplifies the overall manufacturing process and enables scaling up production without the limitations of traditional monolithic array fabrication
Solution Approach 2:
The invention changes the manufacturing parameters by using low melting point materials (wax, gelatin, sugar) that can be easily molded and then removed, leaving hollow microneedle structures. This parameter change from traditional metal or rigid polymer microneedles to melt-formable materials dramatically simplifies the manufacturing process and enables cost-effective mass production
2Manufacturing precision
If microneedles are made with precise dimensions for consistent dosing, then delivery reproducibility is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The invention performs preliminary action by pre-forming microneedles in molds with precise dimensions before assembly into arrays. The microneedles are created with controlled length, diameter, and spacing in the mold stage, ensuring dimensional consistency. This preliminary formation step separates the precision manufacturing requirement from the array assembly process, reducing overall manufacturing complexity
Solution Approach 2:
The invention uses mold cavities as templates to copy the desired microneedle geometry repeatedly. Each mold cavity acts as a master pattern that replicates precise microneedle dimensions across hundreds or thousands of units. This copying approach ensures dimensional consistency through replication rather than through complex manufacturing processes
3Strength
If microneedles are made strong to withstand handling, then structural integrity is maintained, but they require more force to insert into the skin
Solution Approach 1:
The invention applies dynamics by designing microneedles that transition from a rigid state during handling to a flexible or dissolvable state during insertion. Materials like gelatin, sugar, or wax maintain structural integrity at room temperature but become soft or dissolve upon contact with skin moisture or body heat, reducing insertion force while maintaining handling strength
Solution Approach 2:
The invention changes material parameters by selecting substances with temperature-dependent or moisture-dependent mechanical properties. The microneedles exhibit high strength at storage temperature but undergo parameter changes (softening, melting, or dissolution) at body temperature or in contact with skin fluids, enabling easy insertion while maintaining structural integrity during handling and storage
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 enables efficient and cost-effective transdermal delivery of drugs by breaching the stratum corneum, allowing for rapid and sustained absorption, and can be applied over larger areas than traditional microneedle arrays, with potential for localized and controlled release of therapeutic and cosmetic agents.
Implementation Method 1
the particles being rigid, irregular in shape and being angular so that they are capable of penetrating the surface of the skin or of a cornea of the patient
Implementation Method 2
the needles break and remain in the skin, where the formulation dissolves and the active substance is absorbed into the blood stream
Implementation Method 3
particles of a formulation that is soluble or biodegradable in the body
Data Source
AI summary
A preparation for the transdermal delivery of a biologically active substance into the body of a patient comprises particles of a formulation comprising the active substance. The particles are irregular in size and shape and may be produced by a low cost manufacturing method such as grinding from a thin film. The particles are angular, i.e. they have sharp edges and corners that allow them to penetrate the outer layer of the skin when subjected to pressure from a roller or an array of blunt-tipped microstructures. Sucrose may be used as an excipient with the active substance to form suitably rigid and angular particles.