title: Preparation of a solid-in-oil nanosuspension containing L-ascorbic acid as a novel long-term stable topical formulation.
abstract: L-Ascorbic acid (AA, vitamin C) easily decomposes into inactive compounds in aqueous solutions and this has limited its topical use. This work reports the preparation of a solid-in-oil nanosuspension (SONS) containing AA and validation of its basic storage stability. Although AA itself is water-soluble, it can readily be nanosuspended in squalane via complex formation involving a combination of sucrose erucate (i.e. lipophilic surfactant) and sucrose monolaureate (i.e. hydrophilic surfactant) to yield SONS with a very low moisture content (<500 ppm). To extract encapsulated AA, a lipase-based enzymatic degradation technique was used to degrade a formulation phase making it easier for AA to distribute into an extraction solution. Our results demonstrate that almost all the encapsulated AA (95.3%) was readily extracted from the SONS upon addition of medium-chain triglyceride, which offers the possibility of degrading the formulation phase using lipase. Finally, its storage stability study was investigated at 25°C over 90 days under protection from light. An aqueous solution containing AA was used as a control. Compared with the control, the SONS markedly increased the stability of AA due to its low moisture content and, thus, the potential usefulness SONSs as a novel long-term stable topical formulation of AA has been proved.
authors: Department of Pharmaceutics, College of Pharmacy, Shenyang Pharmaceutical University, No. 103, Wenhua Road, Shenyang 110016, China.
authors: Hongyu
authors: H
authors: Piao
authors: Noriho
authors: N
authors: Kamiya
authors: Fude
authors: F
authors: Cui
authors: Masahiro
authors: M
authors: Goto
mesh_terms: D000287:Administration, Topical; D000975:Antioxidants / Q000008:administration & dosage / Q000737:chemistry*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers; D004339:Drug Compounding; D004355:Drug Stability; D004356:Drug Storage; D008049:Lipase / Q000737:chemistry; D053758:Nanoparticles; D036103:Nanotechnology; D009821:Oils / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods; D013696:Temperature; D013997:Time Factors; D014815:Vitamins / Q000008:administration & dosage / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D004337:Drug Carriers; D009821:Oils; D013501:Surface-Active Agents; D014815:Vitamins; D008049:Lipase; D001205:Ascorbic Acid