Liposomes and micro/nanoparticles as colloidal carriers for nasal drug delivery

The use of the nasal route for drug delivery has attracted much interest in recent years in the pharmaceutical field. Local and principally systemic drug delivery can be achieved by this route of administration. But the nasal route of delivery is not applicable to all drugs. Polar drugs and some macromolecules are not absorbed in sufficient concentration due to poor membrane permeability, rapid clearance and enzymatic degradation into the nasal cavity. Thus, alternative means that help overcome these nasal barriers are currently in development. Absorption enhancers such as phospholipids and surfactants are constantly used, but care must be taken in relation to their concentration. Drug delivery systems including liposomes, cyclodextrins, micro- and nanoparticles are being investigated to increase the bioavailability of drugs delivered intranasally. This review article discusses recent progress and specific development issues relating to colloidal drug delivery systems in nasal drug delivery. © 2006 Bentham Science Publishers Ltd.

Surfactant systems for nasal zidovudine delivery: structural, rheological and mucoadhesive properties

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de nanopartículas de quitosana para potencial administração nasal da DISBa-01, uma desintegrina recombinante do veneno da serpente Rhinocerophis alternatus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento e caracterização de sistemas nanoestruturados para potencial administração nasal de zidovudina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preparation and Characterization of Chitosan Nanoparticles for Zidovudine Nasal Delivery

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento de nanopartículas de quitosana para adminstração nasal de zidovudina

Zidovudine (AZT) is the drug most commonly used in AIDS treatment, isolated or in combination with other antiretroviral agents, but it has certain limitations due to its therapeutic dose-dependent haematological toxicity. In addition, it has low oral bioavailability, since it undergoes pre-systemic metabolism. The nasal route has been used as an alternative route for drug administration, because it can promote its direct absorption to blood circulation, avoiding hepatic metabolism. However, this route presents as a factor limiting the mucociliary clearance mechanisms that remove quickly the formulation of the nasal cavity. To prolong the residence time of formulations, in this direction, has been proposed the development of mucoadhesive systems. Among the various existing systems, the use of chitosan (QS), as mucoadhesive polymer, has been widely exploited in the preparation of nanoparticles (NPs). The objective of this study was to develop and characterize QS’s NPs for intranasal administration of AZT. For both NPs have been developed by ionic crosslinking of QS with sodium tripolyphosphate (TPP). These NPs were characterized by studies of particle size distribution, zeta potential, morphology, mucoadhesion tests, assessing the ability of encapsulation of the drug and permeation profile of AZT. The evaluation of AZT in the NPs was determined by UV-Vis spectroscopy. Mucoadhesion measures were made using a texture analyzer, using a mucin disk and porcine mucous membrane , and permeation assay were conducted using porcine nasal mucous membrane adapted to the Franz cell. These results suggest that the systems in hand have great potential for nasal AZT administration

Phosphorus bioavailability in diets for growing horses

A study of phosphorus (P) metabolism was carried out using 12 month old Brasileiro de Hipismo breed of horses to determine the P bioavailability available from feeds commonly fed to horses in Brazil. Five different diets were formulated to contain approximately equivalent levels of crude protein and digestible energy, as well as to supply at least 22 g P/horse/day (NRC, 1989). All 5 diets contained 40% Bermuda coastal hay plus 60% concentrate. The 5 different concentrates contained: C1 (corn+ cottonseed meal) C2 (corn grain+soybean meal) C3 (corn+sugarcane yeast), C4 (oat+cottonseed meal), and C5 (oat+soybean meal). The radioisotope (32)p was injected with 30 NIB. Blood, feces and urine were collected for 7 days to evaluate endogenous fecal P and true absorption. Analysis of variance of P intake showed differences due to dietary effects (P < 0.05). Concentrate C3 had the lowest intake (79.68 mg/ kg BW). All of the diets produced positive P retention. Absolute values for P concentrations in plasma, urine, feces and endogenous feces did not vary between diets. Values for endogenous fecal P were independent of the level of P intake, so the correlation between P intake and P endogenous was not significant. P bioavailability values were 50.75; 40.98; 43.50; 51.03 and 57.68% for diets C1 through C5, respectively. However, differences in P bioavailability were found (P < 0.05) between diets. Diets C2 and C3 had lower P bioavailability than the other diets. The P bioavailability of all dietary treatments in this study exceeded NRC (1989) postulations of 35% true P absorption in diets not supplemented with inorganic P. The results of this study indicate that inorganic P supplementation is not needed for growing yearlings fed common Brazilian feeds. Considering the high cost of P supplementation and the risk of environmental P contamination, inorganic phosphorus supplementation for growing yearlings may not be required. (c) 2007 Elsevier B.V. All rights reserved.

Efeito imediato e a curto prazo do cigarro sobre o transporte mucociliar nasal de fumadores

Background and objectives: The efficiency of mucociliary transport may vary in different conditions, such as in exposure to harmful particles of the cigarette smoke. The present study evaluated the acute and short term effects of smoking on nasal mucociliary clearance in current smokers by the quantification of the Saccharin Transit Time (STT), and to investigate its correlation with the history of tobacco consumption.Methods: Nineteen current smokers (11 men, 51 +/- 16 years; BMI 23 +/- 9 kg/m(2), 27 +/- 11 cigarettes per day, 44 +/- 25 pack-years), entering a smoking cessation intervention program, responded to a questionnaire concerning smoking history and were submitted to lung function assessment (spirometry) and the STT test. STT was assessed immediately after smoking and 8 hours after smoking. The STT test was also performed in nineteen matched healthy non-smokers' who served as control group.Results: When compared to STT in non-smokers' (10 +/- 4 min; mean +/- standard deviation), smokers presented similar STT immediately after smoking (11 +/- 6 min; p = 0.87) and slower SIT 8 hours after smoking (16 +/- 6 min; p = 0.005 versus non-smokers' and p = 0.003 versus immediately after smoking). STT 8 hours after smoking correlated positively with age (r = 0.59; p = 0.007), cigarettes per day (r = 0.53; p = 0.02) and pack-years index (r = 0.74; p = 0.0003).Conclusions: In smokers, although the mucociliary clearance immediately after smoking is similar to non-smokers', eight hours after smoking it is reduced, and this reduction is closely related to the smoking habits. (C) 2010 Sociedade Portuguesa de Pneumologia. Published by Elsevier Espana, S.L. All rights reserved.

Reversibility of impaired nasal mucociliary clearance in smokers following a smoking cessation programme

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mannheimiose pulmonar experimental em bezerros: swab nasal e nasofaringeano como auxílio diagnóstico

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Consequences of Chronic Nasal Obstruction on the Laryngeal Mucosa and Voice Quality of 4- to 12-Year-Old Children

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of selenium by GFAAS in slurries of fish feces to estimate the bioavailability of this micronutrient in feed used in pisciculture

This paper presents a simple, fast and sensitive method to determine selenium in samples of feces and of fish feed by graphite furnace atomic absorption spectrometry (GFAAS) through the direct introduction of slurries of the samples into the spectrometer's graphite tube. The limits of detection (LOD) and quantification (LOQ calculated for 20 readings of the blank of the standard slurries (0.50% m/v of feces or feed devoid of selenium) were 0.31 mu g 1(-1) and 1.03 mu g 1(-1), respectively, for the standard feces slurries and 0.35 mu g 1(-1) and 1.16 mu g 1(-1), respectively, for the standard feed slurries. The proposed method was applied in studies of bioavailability of selenium in different fish feeds and the results proved consistent with that obtained from samples mineralized by acid digestion using the microwave oven. (C) 2007 Elsevier Ltd. All rights reserved.

Solutions for Nasal Defects

Many studies on defects caused by trauma, infection, cancer, or congenital are reported in the literature; in nasal reconstructions, contradictions and distinct techniques exist that can be argued. Using the literature, we observe these distinct techniques that call be surgery or in surgery to reestablish and to integrate the patient with satisfaction in the society.

Photographic assessment of nasal morphology following rapid maxillary expansion in children

Objective: The aim of the present study was to use facial analysis to determine the effects of rapid maxillary expansion (RME) on nasal morphology in children in the stages of primary and mixed dentition, with posterior cross-bite. Material and Methods: Facial photographs (front view and profile) of 60 patients in the pre-expansion period, immediate post-expansion period and one year following rapid maxillary expansion with a Haas appliance were evaluated on 2 occasions by 3 experienced orthodontists independently, with a 2-week interval between evaluations. The examiners were instructed to assess nasal morphology and had no knowledge regarding the content of the study. Intraexanniner and interexanniner agreement (assessed using the Kappa statistic) was acceptable. Results: From the analysis of the mode of the examiners' findings, no alterations in nasal morphology occurred regarding the following aspects: dorsunn of nose, alar base, nasal width of middle third and nasal base. Alterations were only detected in the nasolabial angle in 1.64% of the patients between the pre-expansion and immediate post-expansion photographs. In 4.92% of the patients between the immediate post-expansion period and 1 year following expansion; and in 6.56% of the patients between the pre-expansion period and one year following expansion. Conclusion: RME performed on children in stages of primary and mixed dentition did not have any impact on nasal morphology, as assessed using facial analysis.