PB0524 - Preparation and Characterization of Nanocarriers for Transdermal Delivery of Enoxaparin

Background: Low molecular weight heparins (LMWHs) are anticoagulants, which penetrates the skin poorly due to its relatively large molecular weight, negative charge and hydrophilic nature. Many techniques have been aimed to disrupt and weaken the highly organized lipids in an intact skin among which is the use of drug delivery systems.

Aims: Enoxaparin has till now been given by intravenous or subcutaneous route therapeutically and this project is an attempt to compare the potential of delivering of such a high molecular weight, hydrophilic drug through a vesicular carrier ie ethosomes encapsulating enoxaparin system across the skin.

Methods: Ethosomes encapsulating enoxaparin were prepared and characterized for average particle size, polydispersity index and percentage drug entrapment. The Transmission Electron Microscopy (TEM) of drug loaded vesicles revealed their spherical structure and unilamellarity. The in-vitro release studies showed that there was no burst effect and the percentage drug release increased linearly up to 24 h. The transdermal flux across the rat skin was found to be 20.4±1.1 μg/cm2/hr. The stability profile of the prepared, optimized system was determined for 120 days, which revealed low drug leakage on storage. The in-vivo studies were performed for presence of nanocarriers (encapsulating Rhodamine B) in the skin by fluorescence microscopy.

Results: The results of Fluorescence microscopy are also encouraging in that they clearly indicate the presence of vesicular system in the skin. The results of overall study demonstrated the importance of carrier composition (especially ethanol and oleic acid) on the physicochemical properties, morphology, skin irritation and consequently the effectiveness of vesicular system as a vehicle for transdermal delivery of enoxaparin.

Conclusion(s): The results were quite encouraging and might be an alternative to injections for topical administration of enoxaparin in case of superficial thrombosis, subcutaneous wounds, bruices and burns. Additional studies should be performed in a clinical setting.