MANUFACTURING
Proposome, an Efficient and Safe Topical Formulation The study developed a nanosized vehicle named'proposome' to enhance the skin absorption of drugs. Proposomes are propylene glycol-based liposomes. The study investigated the skin permeation of proposomes loaded with ibuprofen, tofacitinib citrate, rhodamine B, and lidocaine. These drugs have different physicochemical properties, which was needed to observe the differences in skin absorption of drugs loaded in proposomes. The proposomes had an average diameter of 128 to 148 nm, measured using dynamic light scattering. The drug entrapment in proposomes varied between 42.9 and 52.7 per cent at the same total concentration, enhancing drug delivery by 1.4 to 4.0 times than free drugs. The skin absorption enhancement through proposomes was linearly correlated with the physicochemical properties of the loadeddrugs. Confocal imaging also confirmed higher skin permeation using proposome than free molecules. The safety of the proposomes was assessed using bioengineered reconstructed human skin tissue equivalents thatshowed proposome was safe for skin application. The enhancement of skin delivery of loaded drugs depended on the drug's lipophilicity, which affected drug entrapment efficiency into proposomes, and in turn drug absorption through skin. Himanshu Kathuria, Department of Pharmacy, National University of Singapore Lifeng Kang, School of Pharmacy, Faculty of Medicine and Health, University of Sydney
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opical delivery is the most acceptable route for treating skin conditions as it provides localized and fast effects. However, the drug delivery through the skin is challenged by the skin outermost layer, which is made up of dead cellsand the lipid matrix. This outermost layer is a primary barrier for therapeutics absorption into the skin, allowingonly small and lipophilic molecules to be absorbed. Various approaches have been developed to overcome this barrier to enhance the skin absorption of therapeutics. Enhanced absorption translates into desired therapeutic effect or fast effect.
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P H A RM A F O C U S A S I A
ISSUE 44 46 - 2021 2022
