ABSTRACT
The high hygroscopicity of gentamicin (G) as raw material hampers the production of respirable particles during aerosol generation and prevents its direct use as powder for inhalation in patients suffering from cystic fibrosis (CF). Therefore, this research aimed to design a new dry powder formulation of G studying dispersibility properties of an aminoacid, L-leucine (leu), and appropriate process conditions. Spray-dried powders were characterized as to water uptake, particle size distribution, morphology and stability, in correlation with process parameters. Aerodynamic properties were analyzed both by Single Stage Glass Impinger and Andersen Cascade Impactor. Moreover, the potential cytotoxicity on bronchial epithelial cells bearing a CFTR F508/F508 mutant genotype (CuFi1) were tested. Results indicated that leu may improve the aerosol performance of G-dried powders. The maximum fine particle fraction (FPF) of about 58.3% was obtained when water/isopropyl alcohol 7:3 system and 15-20% (w/w) of leu were used, compared to a FPF value of 13.4% for neat G-dried powders. The enhancement of aerosol efficiency was credited both to the improvement of the powder flowability, caused by the dispersibility enhancer (aminoacid), and to the modification of the particle surface due to the influence of the organic co-solvent on drying process. No significant degradation of the dry powder was observed up to 6 months of storage. Moreover, particle engineering did not affect either the cell viability or cell proliferation of CuFi1 over a 24 h period.
Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/toxicity , Dry Powder Inhalers , Excipients/chemistry , Excipients/toxicity , Gentamicins/chemistry , Gentamicins/toxicity , Leucine/chemistry , Leucine/toxicity , Respiratory Mucosa/drug effects , 2-Propanol/chemistry , Administration, Inhalation , Aerosols , Anti-Bacterial Agents/administration & dosage , Cell Line , Cell Proliferation/drug effects , Cell Survival/drug effects , Chemistry, Pharmaceutical , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Dose-Response Relationship, Drug , Drug Compounding , Drug Stability , Gentamicins/administration & dosage , Humans , Mutation , Particle Size , Powders , Respiratory Mucosa/metabolism , Respiratory Mucosa/pathology , Risk Assessment , Solvents/chemistry , Technology, Pharmaceutical/methods , Time Factors , Water/chemistryABSTRACT
Flavonoids, natural compounds widely distributed in the plant kingdom, are reported to affect the inflammatory process and to possess anti-inflammatory as well as immunomodulatory activity in-vitro and in-vivo. Since nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) is one of the inflammatory mediators, the effects of the ethanol/water (1:1) extract of the leaves of Apium graveolens var. dulce (celery) on iNOS expression and NO production in the J774.A1 macrophage cell line stimulated for 24 h with Escherichia coli lipopolysaccharide (LPS) were evaluated. The extract of A. graveolens var. dulce contained apiin as the major constituent (1.12%, w/w, of the extract). The extract and apiin showed significant inhibitory activity on nitrite (NO) production in-vitro (IC50 0.073 and 0.08 mg mL(-1) for the extract and apiin, respectively) and iNOS expression (IC50 0.095 and 0.049 mg mL(-1) for the extract and apiin, respectively) in LPS-activated J774.A1 cells. The croton-oil ear test on mice showed that the extract exerted anti-inflammatory activity in-vivo (ID50 730 microg cm(-2)), with a potency seven-times lower than that of indometacin (ID50 93 microg cm(-2)), the non-steroidal anti-inflammatory drug used as reference. Our results clearly indicated the inhibitory activity of the extract and apiin in-vitro on iNOS expression and nitrite production when added before LPS stimulation in the medium of J774.A1 cells. The anti-inflammatory properties of the extract demonstrated in-vivo might have been due to reduction of iNOS enzyme expression.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Apium/chemistry , Flavonoids/pharmacology , Nitric Oxide Synthase Type II/biosynthesis , Phenols/pharmacology , Animals , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Cell Line , Cell Survival/drug effects , Chromatography, High Pressure Liquid , Escherichia coli , Flavonoids/chemistry , Humans , Lipopolysaccharides/pharmacology , Macrophages/metabolism , Mice , Nitric Oxide/antagonists & inhibitors , Nitric Oxide/biosynthesis , Nitric Oxide Synthase Type II/antagonists & inhibitors , Phenols/chemistry , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Leaves , Plants, EdibleABSTRACT
Lannea microcarpa (Anacardiaceae) is a tropical tree used in African folk medicine and commercial dermopharmaceutical formulations. Fractionation and analysis of its polar extract allowed the identification of 4'-methoxy-myricetin 3-O-alpha-L-rhamnopyranoside, myricetin 3-O-alpha-L-rhamnopyranoside, myricetin 3-O-beta-D-glucopyranoside, vitexin, isovitexin, gallic acid and epi-catechin, as the major constituents. In-vivo assay (the croton oil ear test in mice) showed that the extract had significant anti-inflammatory effect (ID50 = 900 microg cm(-2)) but ten times lower than that of indometacin (ID50 = 93 microg cm(-2)), the non-steroidal anti-inflammatory drug used as reference. Cytotoxicity and cutaneous irritation of the extract and its constituents were investigated. The crude extract and its major components did not affect cell viability in-vitro either in three different cultures (J774. A1, WEHI-164 and HEK-293) of cells grown in monolayers or in the reconstituted human epidermis (RHE, 3D model), nor did they cause release of pro-inflammatory mediators (IL-1alpha) or histomorphological modification of RHE.
