A proposed model membrane and test method for microneedle insertion studies
Eneko Larrañeta1, Jessica Moore1, Eva M Vicente-Pérez1
1Queens University, Belfast School of Pharmacy, 97 Lisburn Road, Belfast BT9 7BL, United Kingdom.
Abstract:
A commercial polymeric film (Parafilm M(®), a blend of a hydrocarbon wax and a polyolefin) was evaluated as a model membrane for microneedle (MN) insertion studies. Polymeric MN arrays were inserted into Parafilm M(®) (PF) and also into excised neonatal porcine skin. Parafilm M(®) was folded before the insertions to closely approximate thickness of the excised skin. Insertion depths were evaluated using optical coherence tomography (OCT) using either a force applied by a Texture Analyser or by a group of human volunteers. The obtained insertion depths were, in general, slightly lower, especially for higher forces, for PF than for skin. However, this difference was not a large, being less than the 10% of the needle length. Therefore, all these data indicate that this model membrane could be a good alternative to biological tissue for MN insertion studies. As an alternative method to OCT, light microscopy was used to evaluate the insertion depths of MN in the model membrane. This provided a rapid, simple method to compare different MN formulations. The use of Parafilm M(®), in conjunction with a standardised force/time profile applied by a Texture Analyser, could provide the basis for a rapid MN quality control test suitable for in-process use. It could also be used as a comparative test of insertion efficiency between candidate MN formulations.
Insights
Parafilm M(®) is a viable model membrane for microneedle (MN) insertion studies, showing comparable results to biological skin. This offers a rapid, cost-effective method for MN quality control and formulation comparison.
Area of Science:
- Biomaterials Science
- Drug Delivery Systems
- Medical Device Testing
Background:
- Microneedle (MN) insertion studies require reliable model membranes for efficient testing.
- Evaluating MN insertion into biological tissues can be complex and costly.
- Parafilm M(®) (PF), a blend of hydrocarbon wax and polyolefin, is explored as a potential alternative.
Purpose of the Study:
- To evaluate Parafilm M(®) as a model membrane for microneedle insertion studies.
- To compare MN insertion depths into Parafilm M(®) and excised neonatal porcine skin.
- To assess the utility of Parafilm M(®) for rapid MN quality control and formulation comparison.
Main Methods:
- Polymeric MN arrays were inserted into Parafilm M(®) and excised neonatal porcine skin.
- Parafilm M(®) was folded to mimic skin thickness.
- Insertion depths were measured using optical coherence tomography (OCT) and light microscopy.
- Forces were applied using a Texture Analyser and by human volunteers.
Main Results:
- MN insertion depths in Parafilm M(®) were slightly lower than in skin, with differences less than 10% of needle length.
- Light microscopy provided a rapid, simple method for evaluating insertion depths.
- Parafilm M(®) insertion depths correlated well with skin, especially under standardized force/time profiles.
Conclusions:
- Parafilm M(®) serves as a suitable and cost-effective model membrane for microneedle insertion studies.
- This model membrane facilitates rapid quality control and comparative testing of microneedle formulations.
- The use of Parafilm M(®) can streamline microneedle research and development processes.
