Liposomal Gel for enhancing topical efficacy of timolol maleate against proliferating superficial infantile hemangiomas.
The TM-lipogel shows promise for enhanced transdermal delivery and tumor regression in a murine model, but its efficacy in humans is yet to be established.
Where it sits
this study against the rest of the melanotan 1 corpusSummary and findings
This study evaluated a novel 0.5% timolol maleate (TM)-loaded liposomal gel for its transdermal efficacy against superficial infantile hemangiomas. The TM-lipogel demonstrated a 1.9-fold increase in cumulative transdermal delivery compared to TM-gel and a 4-fold increase compared to TM solution. In a murine model, the TM-lipogel achieved an 81.09% tumor regression compared to 29.85% for TM-eyedrop and 61.69% for TM-gel.
Abstract
Conventional timolol maleate (TM) eye drops are limited by low transdermal bioavailability and short dermal residence time for the treatment of superficial infantile hemangioma (IH). To address this, a novel 0.5% TM-loaded liposomal gel (TM-lipogel) was developed by embedding optimized liposomes within a carbomer gel matrix. The TM-liposomes exhibited a desirable particle size of 139.5 ± 2.1 nm, a polydispersity index (PDI) of 0.051, a zeta potential of -38.7 mV, and an encapsulation efficiency of 64.76 ± 3.2%. <i>Ex vivo</i> permeation studies revealed a 1.9-fold increase in cumulative transdermal delivery compared to the TM-gel, and 4-fold compared to the TM solution (<i>p</i> < 0.05). Furthermore, confocal laser scanning microscope imaging revealed that TM-lipogel achieved a penetration depth of 400 μm, while the TM-gel and TM-eyedrop only reached 200 μm and 75 μm, respectively, highlighting the superior penetration of the liposomal gel. In a murine xenograft hemangioma model, 0.5% TM-lipogel achieved superior tumor regression (81.09%, <i>p</i> < 0.01 <i>vs.</i>control) compared to 0.5% TM-eyedrop (29.85%) and 0.5% TM-gel (61.69%) by simultaneously downregulating HIF-1α, VEGF, MMP-9 and eNOS. Critically, the optimized formulation exhibited no skin irritation and no systemic toxicity. These findings highlight that the TM-lipogel provides enhanced transdermal delivery with deeper tissue penetration, representing a highly effective and safe transdermal strategy for IH therapy.
Background
This paper addresses the limitations of conventional timolol maleate eye drops, which have low transdermal bioavailability and short dermal residence time for treating superficial infantile hemangiomas. Previous studies have indicated that enhanced delivery systems could improve therapeutic outcomes. The development of a liposomal gel aims to provide a more effective treatment option, warranting investigation into its efficacy and safety.
Methods
The study involved the development of a 0.5% TM-loaded liposomal gel embedded in a carbomer gel matrix. Ex vivo permeation studies were conducted to assess transdermal delivery, and a murine xenograft hemangioma model was used for in vivo efficacy evaluation. The primary outcome was tumor regression percentage, with secondary outcomes including penetration depth and encapsulation efficiency.
Results
The TM-lipogel achieved an 81.09% tumor regression, p<0.01 compared to control. The TM-gel and TM-eyedrop resulted in tumor regression of 61.69% and 29.85%, respectively. Penetration depth was measured at 400 μm for TM-lipogel, while TM-gel and TM-eyedrop reached 200 μm and 75 μm, respectively. The encapsulation efficiency was reported at 64.76 ± 3.2%.
Interpretation
The findings suggest that the TM-lipogel significantly enhances transdermal delivery and tumor regression compared to traditional formulations. However, while the statistical significance is noted, the clinical relevance of these findings in human subjects remains uncertain. The study's reliance on a murine model and the absence of human data limit the applicability of these results in clinical practice.
Key findings
- TM-liposomes exhibited a particle size of 139.5 ± 2.1 nm.
- Encapsulation efficiency was 64.76 ± 3.2%.
- Cumulative transdermal delivery increased 1.9-fold compared to TM-gel, p<0.05.
- Cumulative transdermal delivery increased 4-fold compared to TM solution, p<0.05.
- TM-lipogel achieved 81.09% tumor regression, p<0.01 vs. control.
- TM-gel achieved 61.69% tumor regression.
Limitations
- Murine model may not fully translate to human outcomes.
- No human data reported.
- Short follow-up duration in animal model.