title: Effect of Liquid Crystalline Systems Containing Antimicrobial Compounds on Infectious Skin Bacteria.
abstract: This study aimed (i) to prepare liquid crystalline systems (LCS) of glyceryl monooleate (GMO) and water containing antibacterial compounds and (ii) to evaluate their potential as drug delivery systems for topical treatment of bacterial infections. Therefore, LCS containing CPC (cetylpyridinium chloride) (LCS/CPC) and PHMB (poly(hexamethylene biguanide) hydrochloride) (LCS/PHMB) were prepared and the liquid crystalline phases were identified by polarizing light microscopy 24 h and 7 days after preparation. The in vitro drug release profile and in vitro antibacterial activity of the systems were assessed using the double layer agar diffusion method against Staphylococcus aureus, methicillin-resistant S. aureus, Staphylococcus epidermidis, Escherichia coli, and Enterococcus faecalis. The interaction between GMO and the drugs was evaluated by a drug absorption study. Stable liquid crystalline systems containing CPC and PHMB were obtained. LCS/PHMB decreased the PHMB release rate and exerted strong antibacterial activity against all the investigated bacteria. In contrast, CPC interacted with GMO so strongly that it became attached to the system; the amount released was not sufficient to exert antibacterial activity. Therefore, the studied liquid crystalline systems were suitable to deliver PHMB, but not CPC. Accordingly, it was demonstrated that GMO interacts with each drug differently, which may interfere in the final efficiency of GMO/water LCS.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Block S, Lab 60, Av. do Café, s/n, Bairro Monte Alegre, Ribeirão Preto, 14040-903, SP, Brazil.
authors.forename: Carla
authors.initials: C
authors.lastname: Souza
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Evandro
authors.initials: E
authors.lastname: Watanabe
authors.affiliation: Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Carolina Patrícia
authors.initials: CP
authors.lastname: Aires
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Block S, Lab 60, Av. do Café, s/n, Bairro Monte Alegre, Ribeirão Preto, 14040-903, SP, Brazil. mlara@fcfrp.usp.br.
authors.forename: Marilisa Guimarães
authors.initials: MG
authors.lastname: Lara
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D001419:Bacteria / Q000145:classification / Q000187:drug effects; D016503:Drug Delivery Systems / Q000379:methods*; D065546:Drug Liberation; D005989:Glycerides / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D050866:Liquid Crystals / Q000737:chemistry; D015203:Reproducibility of Results; D012874:Skin Diseases, Infectious / Q000188:drug therapy*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D005989:Glycerides; C005953:monoolein
keywords: cetylpyridinium chloride; drug delivery systems; glyceryl monooleate; liquid crystalline systems; poly(hexamethylene biguanide) hydrochloride