Inhibitory effects of theophylline, terbutaline, and hydrocortisone on leukotriene B4 and C4 generation by human leukocytes in vitro

Formulation and optimization of theophylline-loaded enteric-coated spanlastic nanovesicles for colon delivery; Ameliorate acetic acid-induced ulcerative colitis

Treatment of colon diseases presents one of the most significant obstacles to drug delivery due to the inability to deliver sufficient drug concentration selectively to the colon. The goal of the proposed study was to develop, optimize, and assess an effective colon target delivery system of theophylline-based nanovesicles (TP-NVs) surrounded by a biodegradable polymeric shell of chitosan (CS) and Eudragit L100 (EL100) for the treatment of ulcerative colitis (UC). TP-loaded nanovesicles were fabricated using the ethanol injection method and coated with CS and EL100, respectively. We used a 32-factorial design approach to optimize the concentration of CS and EL100 to minimize particle size (PS) and maximize the cumulative amount of theophylline released (CTR) after 24 h. The optimized formulation was described using transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and in vitro release. In-vivo quantification of theophylline in the gastrointestinal tract and in-vivo targeting potential in a rat model of acetic acid-induced colitis were also thoroughly evaluated. The characteristics of the optimal formula predicted by the 32-factorial design approach corresponded exceptionally well with the measured PS of 271.3 nm, the zeta potential of -39.9 mV, and CTR of 3.95, and a 99.93% after 5 and 24 h, respectively. Notably, the in vivo results in the rat model of colitis showed that the formulation with an optimized coat significantly improved theophylline distribution to the colon and markedly decreased the expression of interleukin-6 and ulcerative lesions compared to a pure theophylline solution. These outcomes elucidated the feasibility of a 32-factorial design to detect the crucial interactions between the study's components. Our findings suggested that enteric-coated nanovesicles formulations with optimal coat compositions of 0.2693% (w/v) and 0.75% (w/v) of CS and EL100, respectively, were promising carriers for colonic delivery of theophylline, a rate-limiting step in the treatment of UC.

Loss of response to treatment with leukotriene receptor antagonists but not inhaled corticosteroids in patients over 50 years of age

BACKGROUND

There are limited published data describing the relative efficacy of available treatment options in younger versus older patients with persistent asthma.

OBJECTIVE

To compare the efficacy of fluticasone propionate (FP) and zafirlukast (Z) in younger (12 to 49 years of age) versus older (50 years and older) patients with asthma.

METHODS

A retrospective analysis of five randomized, double-blind, double-dummy studies 4 to 12 weeks in duration of 1,742 patients <50 years of age and 243 patients aged 50 years or older. Interventions were inhaled fluticasone propionate (FP) 88 microg, oral Z 20 mg, or placebo twice daily.

RESULTS

Treatment with FP resulted in significantly greater improvements than Z in all efficacy measurements (except for nighttime awakenings) regardless of age. In older patients, treatment with FP significantly increased pulmonary function compared with Z: FEV (FP= +0.19 L; placebo = -0.34 L; Z = -0.06 L); AM peak expiratory flow rate [PEFR] (FP = +25 L/minute; placebo = -18 L/minute; Z = +4 L/minute); PM PEFR (FP = +24 L/minute; placebo = -24 L/minute; Z = +5 L/minute; P < or = 0.023; for all comparisons). Compared with Z, treatment with FP in older patients also resulted in significantly greater increases in the percentage of symptom-free days (25% vs 13%) and rescue-free days (35% vs 17%); and significantly greater reductions in albuterol use (-1.6 vs -0.3 puffs/day) and the percentage of patients with exacerbations (2.7% vs 14.3%; P < or = 0.031).

CONCLUSIONS

Regardless of age, treatment with FP in patients with asthma significantly improved pulmonary function and overall asthma control. In contrast, treatment with Z in older patients with asthma resulted in small improvements in asthma symptoms, whereas lung function improved minimally or not at all, and exacerbations increased. These data suggest that FP effectively controls inflammation in older patients, whereas Z may mask inflammation and may not provide the level of bronchodilatory or anti-inflammatory activity needed for effective asthma control in older patients.

The effects of an endurance ride on metabolism and neutrophil function

The effects of an endurance ride on neutrophil functions in endurance-trained horses were evaluated and related to metabolic changes and changes in cortisol concentrations. Blood samples were taken from 7 horses (aged 9-15 years) one day before, and then 30-60 min, 1 day and 8 days after the ride. The race resulted in elevated serum cortisol levels (< 465 nmol/l) and an increased neutrophil:lymphocyte ratio. Immediately post race, the neutrophil ability to engulf yeast was increased. One day after the race, a decrease in leukotriene B4 production (approximately 40%) and in the respiratory burst (approximately 75%) was observed. Blood glucose concentration remained unchanged, as did serum lactate, which was low. After the race, the muscle glycogen stores were about 33% of the values noted after 8 days of recovery. Histochemical staining showed that 22 +/- 2% of the muscle fibres were totally depleted of glycogen. CK activity increased significantly from 40 +/- 10 mmol/min pre-race to 228 +/- 38 mmol/min post race. It was concluded that both hormonal and metabolic changes occurred during an endurance ride, which not only triggered neutrophil activation, but also induced alterations in their functional capacities.