Increased In Situ Intestinal Absorption of Phytoestrogenic Diarylheptanoids from Curcuma comosa in Nanoemulsions

Curcuma comosa has long been used as a gynecological medicine. Several diarylheptanoids have been purified from this plant, and their pharmacological effects were proven. However, there is no information about the absorption of C. comosa components to support the formulation usage. In the present study, C. comosa hexane extract and the mixture of its two major compounds, (4E,6E)-1,7-diphenylhepta-4,6-dien-3-ol (DA1) and (6E)-1,7-diphenylhept-6-en-3-ol (DA2), were formulated into nanoemulsions. The physical properties of the nanoemulsions and the in situ intestinal absorptions of DA1 and DA2 were evaluated. The results demonstrated the mean particle sizes at 0.207 ± 0.001 and 0.408 ± 0.014 μm, and the zeta potential at −14.57 ± 0.85 and −10.47 ± 0.32 mV for C. comosa nanoemulsion (C.c-Nano) and mixture of diarlylheptanoid nanoemulsions (DA-Nano), respectively. The entrapments of DA1 and DA2 were 76.61% and 75.41%, and 71.91% and 71.63% for C.c-Nano and DA-Nano, respectively. The drug loading ratios of DA1 and DA2 were 351.47 and 614.53 μg/mg, and 59.48 and 126.72 μg/mg for C.c-Nano and DA-Nano. The intestinal absorption rates of DA1 and DA2 were 0.329 ± 0.015 and 0.519 ± 0.026 μg/min/cm² in C.c-Nano, and 0.380 ± 0.006 and 0.428 ± 0.036 μg/min/cm² in DA-Nano, which were five to ten times faster than those in oil. In conclusion, the formulation in nanoemulsion forms obviously increased the intestinal absorption rate of diarylheptanoids.KEY WORDS: Curcuma comosa, diarylheptanoids, intestinal absorption, nanoemulsion, phytoestrogen     

Nanoemulsion for Solubilization,Stabilization, and In Vitro Release of Pterostilbene for Oral Delivery

Pterostilbene, being extracted from many plants, has significant biological activities in preventing cancer, diabetes, and cardiovascular diseases so as to have great potential applications in pharmaceutical fields. But the poor solubility and stability of pterostilbene strictly restrained its applications. As a good protection and oral delivery system, an optimal nanoemulsion for pterostilbene was developed by using low-energy emulsification method. Systematic pseudo-ternary phase diagrams have been studied in optimization of nanoemulsion formulations. The prepared pterostilbene nanoemulsion was characterized by transmission electron microscope, Fourier transform Raman spectrum, and laser droplet size analyzer. Nanoemulsion droplets are circular with smooth margin, and the mean size is 55.8 ± 10.5 nm. The results illustrated that the nanoemulsion as oral delivery system dramatically improved the stability and solubility of pterostilbene, and in vitro release of pterostilbene was significantly improved (96.5% in pH 3.6 buffer; 13.2% in pH 7.4 buffer) in comparison to the pterostilbene suspension (lower than 21.4% in pH 3.6 buffer; 2.6% in pH 7.4 buffer).KEY WORDS: 3,5-dimethoxyl-4′-hydroxystilbene, nanoemulsion, pseudo-ternary phase diagram, pterostilbene, release study     

Exercise reduces cellular stress related to skeletal muscle insulin resistance

This study sought to evaluate the effects of a single session of exercise on the expression of Hsp70, of c-jun N-terminal kinase (JNK), and insulin receptor substrate 1 serine 612 (IRS^ser612) phosphorylation in the skeletal muscle of obese and obese insulin-resistant patients. Twenty-seven volunteers were divided into three experimental groups (eutrophic insulin-sensitive, obese insulin-sensitive, and obese insulin-resistant) according to their body mass index and the presence of insulin resistance. The volunteers performed 60 min of aerobic exercise on a cycle ergometer at 60 % of peak oxygen consumption. M. vastus lateralis samples were obtained before and after exercise. The protein expressions were evaluated by Western blot. Our findings show that compared with paired eutrophic controls, obese subjects have higher basal levels of p-JNK (100 ± 23 % vs. 227 ± 67 %, p = 0.03) and p-IRS-1^ser612 (100 ± 23 % vs. 340 ± 67 %, p < 0.001) and reduced HSP70 (100 ± 16 % vs. 63 ± 12 %, p < 0.001). The presence of insulin resistance results in a further increase in p-JNK (460 ± 107 %, p < 0.001) and a decrease in Hsp70 (46 ± 5 %, p = 0.006), but p-IRS-1^ser612 levels did not differ from obese subjects (312 ± 73 %, p > 0.05). Exercise reduced p-JNK in obese insulin-resistant subjects (328 ± 33 %, p = 0.001), but not in controls or obese subjects. Furthermore, exercise reduced p-IRS-1^ser612 for both obese (122 ± 44 %) and obese insulin-resistant (185 ± 36 %) subjects. A main effect of exercise was observed in HSP70 (p = 0.007). We demonstrated that a single session of exercise promotes changes that characterize a reduction in cellular stress that may contribute to exercise-induced increase in insulin sensitivity.     

Moderate- and high-intensity exhaustive exercise in the heat induce a similar increase in monocyte Hsp72

This study examined the relationship between exhaustive exercise in the heat at moderate and high intensities on the intracellular heat shock protein 72 (iHsp72) response. Twelve male subjects cycled to exhaustion at 60 and 75 % of maximal oxygen uptake in hot conditions (40 °C, 50 % RH). iHsp72 concentration was measured in monocytes before, at exhaustion and 24 h after exercise. Rectal temperature, heart rate and oxygen uptake were recorded during exercise. Volitional exhaustion occurred at 58.9 ± 12.1 and 27.3 ± 9.5 min (P < 0.001) and a rectal temperature of 39.8 ± 0.4 and 39.2 ± 0.6 °C (P = 0.002), respectively, for 60 and 75 %. The area under the curve above a rectal temperature of 38.5 °C was greater at 60 % (17.5 ± 6.6 °C min) than 75 % (3.4 ± 4.8 °C min; P < 0.001), whereas the rate of increase in rectal temperature was greater at 75 % (5.1 ± 1.7 vs. 2.2 ± 1.4 °C h⁻¹; P < 0.001). iHsp72 concentration increased similarly at exhaustion relative to pre-exercise (P = 0.044) and then increased further at 24 h (P < 0.001). Multiple regression analysis revealed no predictor variables associated with iHsp72 expression; however, a correlation was observed between exercise intensities for the increase in iHsp expression at exhaustion and 24 h (P < 0.05). These results suggest that iHsp72 expression increased in relation to the level of hyperthermia attained and sustained at 60 % and the higher metabolic rate and greater rate of increase in core temperature at 75 %, with the further increase in iHsp72 concentration 24 h after exercise reinforcing its role as a chaperone and cytoprotective agent.     

Development and Clinical Evaluation of Clotrimazole–β-Cyclodextrin Eyedrops for the Treatment of Fungal Keratitis

Fungal keratitis is a serious corneal disease that may result in loss of vision. There are limited treatment options available in Iraqi eye hospitals which might be the main reason behind the poor prognosis of many cases. The purpose of this study was to prepare and pharmaceutically evaluate clotrimazole–β-cyclodextrin (CTZ–β-CD) eyedrops then clinically assess its therapeutic efficacy on fungal keratitis compared with extemporaneous amphotericin B eyedrops (0.5% w/v). A CTZ–β-CD ophthalmic solution was prepared and evaluated by various physicochemical, microbiological, and biological tests. The prepared formula was stable in 0.05 M phosphate buffer pH 7.0 at 40 ± 2°C and 75 ± 5% RH for a period of 6 months. Light has no significant effect on the formula’s stability. The CTZ–β-CD eyedrops efficiently complied with the isotonicity, sterility, and antimicrobiological preservative effectiveness tests. Results of the clinical study revealed that 20 (80%) patients showed a favorable response to the CTZ–β-CD eyedrops, while 16 patients (64%) exhibited a favorable response to amphotericin B (P > 0.05). The mean course of treatment was significantly (P < 0.05) less in the CTZ treatment group than in the amphotericin group (21.5 ± 5.2 vs. 28.3 ± 6.4 days, respectively). The CTZ formulation was significantly (P < 0.05) more effective in the management of severe cases and also against Candida sp. than amphotericin B. There was no significant difference (P < 0.05) between both therapies against filamentous fungi. The CTZ–β-CD formulation can be used alternatively to other ophthalmic antimycotic treatment options in developing countries where stability, cost, or efficacy is a limiting factor.Key words: clotrimazole, β-cyclodextrin, eyedrops, fungal keratitis, Iraq     

An Excellent Delivery System for Improving the Oral Bioavailability of Natural Vitamin E in Rats

This study set out to develop a novel and stable nanoemulsion formulation of natural vitamin E with increased oral bioavailability. The natural vitamin E nanoemulsion was prepared by a modified emulsification technique. The physicochemical characteristics of natural vitamin E nanoemulsion were characterized and its pharmacokinetics study was performed as well. The experimental results showed droplet diameters ranging from 20 to 400 nm (average, 87.7 nm) with a negative electrostatic potential (−23.5 ± 1.5 mv). The pharmacokinetics study of this nanoemulsion and corresponding soft capsule was carried out using noncompartment model method. Compared with the marketed soft capsule, the C_max of the natural vitamin E nanoemulsion was higher, while the T_max was shorter. Thus, plasma concentration–time profiles in rats dosed with nanoemulsion showed a 1.6-fold enhancement in the area under the curve of natural vitamin E compared with the marketed soft capsule. The antioxidative effects of the natural vitamin E nanoemulsion and the marketed soft capsule were also evaluated by the levels of superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentration in serum and liver tissue. According to the SOD activity and the MDA concentration determined, the nanoemulsion was superior to the marketed soft as an antioxidative agent. The overall results demonstrated that the nanoemulsion drug delivery system could be a promising strategy for the delivery of natural vitamin E, which showed great potential for clinical application.Key word: Antioxidation, Nanoemulsion, Natural vitamin E, Oral bioavailability     

Heat and exercise acclimation increases intracellular levels of Hsp72 and inhibits exercise-induced increase in intracellular and plasma Hsp72 in humans

In order to verify the effects of heat and exercise acclimation (HA) on resting and exercise-induced expression of plasma and leukocyte heat shock protein 72 (Hsp72) in humans, nine healthy young male volunteers (25.0 ± 0.7 years; 80.5 ± 2.0 kg; 180 ± 2 cm, mean ± SE) exercised for 60 min in a hot, dry environment (40 ± 0°C and 45 ± 0% relative humidity) for 11 days. The protocol consisted of running on a treadmill using a controlled hyperthermia technique in which the work rate was adjusted to elevate the rectal temperature by 1°C in 30 min and maintain it elevated for another 30 min. Before and after the HA, the volunteers performed a heat stress test (HST) at 50% of their individual maximal power output for 90 min in the same environment. Blood was drawn before (REST), immediately after (POST) and 1 h after (1 h POST) HST, and plasma and leukocytes were separated and stored. Subjects showed expected adaptations to HA: reduced exercise rectal and mean skin temperatures and heart rate, and augmented sweat rate and exercise tolerance. In HST1, plasma Hsp72 increased from REST to POST and then returned to resting values 1 h POST (REST: 1.11 ± 0.07, POST: 1.48 ± 0.10, 1 h POST: 1.22 ± 0.11 ng mL⁻¹; p < 0.05). In HST2, there was no change in plasma Hsp72 (REST: 0.94 ± 0.08, POST: 1.20 ± 0.15, 1 h POST: 1.17 ± 0.16 ng mL⁻¹; p > 0.05). HA increased resting levels of intracellular Hsp72 (HST1: 1 ± 0.02 and HST2: 4.2 ± 1.2 density units, p < 0.05). Exercise-induced increased intracellular Hsp72 expression was observed on HST1 (HST1: REST, 1 ± 0.02 vs. POST, 2.9 ± 0.9 density units, mean ± SE, p < 0.05) but was inhibited on HST2 (HST2: REST, 4.2 ± 1.2 vs. POST, 4.4 ± 1.1 density units, p > 0.05). Regression analysis showed that the lower the pre-exercise expression of intracellular Hsp72, the higher the exercise-induced increase (R = −0.85, p < 0.05). In conclusion, HA increased resting leukocyte Hsp72 levels and inhibited exercise-induced expression. This intracellular adaptation probably induces thermotolerance. In addition, the non-increase in plasma Hsp72 after HA may be related to lower stress at the cellular level in the acclimated individuals.     

Relative Bioavailability of Chlorothiazide from Mucoadhesive Compacts in Pigs

The relative bioavailability of chlorothiazide from mucoadhesive polymeric compacts is compared to commercial oral suspension in pigs. A single-dose randomized study was conducted in 12 healthy pigs that are 9–10 weeks old. After overnight fasting, pigs were divided into two groups of six animals. To the first group, a reference product containing 50 mg of chlorothiazide suspension, and in the second group, test product (mucoadhesive compacts) chlorothiazide (50 mg) was administered with 75 mL of water via gastric tubes. Blood samples were collected between 0 to 24 h using catheters inserted into the jugular vein. Plasma was separated by protein precipitation, and chlorothiazide concentrations were determined using a high-performance liquid chromatography method. The mean T_max and the C_max of chlorothiazide following the administration of oral suspension and mucoadhesive compacts were 0.58 ± 0.20 h and 682.97 ± 415.69 ng/mL and 2.17 ± 0.98 h and 99.42 ± 124.08 ng/mL, respectively. The K_el and T_1/2 of chlorothiazide were found to be 1.06 ± 0.28 h⁻¹ and 0.70 ± 0.21 h from suspension and 0.95 ± 1.11 h⁻¹ and 2.05 ± 1.90 h from the compacts, respectively. The T_max of mucoadhesive compacts were significantly longer (p < 0.05; 2.17 h) than the reference products (0.58 h), whereas the C_max of compacts were significantly lower (99 ng/mL) than the reference product (683 ng/mL; p < 0.05). The area under the curve (AUC) of compacts accounts only 50.15% (404.32 ± 449.93 ng h/mL) of the reference product’s AUC (806.27 ± 395.97 ng h/mL). The relative bioavailability of the compacts was lower than that of the suspension, and this may be due to the narrow window of absorption for chlorothiazide.Key words: bioavailability, chlorothiazide, mucoadhesive compacts, pigs     

Positively Charged Polymeric Nanoparticle Reservoirs of Terbinafine Hydrochloride: Preclinical Implications for Controlled Drug Delivery in the Aqueous Humor of Rabbits

Frequent instillation of terbinafine hydrochloride (T HCl) eye drops (0.25%, w/v) is necessary to maintain effective aqueous humor concentrations for treatment of fungal keratitis. The current approach aimed at developing potential positively charged controlled-release polymeric nanoparticles (NPs) of T HCl. The estimation of the drug pharmacokinetics in the aqueous humor following ocular instillation of the best-achieved NPs in rabbits was another goal. Eighteen drug-loaded (0.50%, w/v) formulae were fabricated by the nanopreciptation method using Eudragit® RS100 and chitosan (0.25%, 0.5%, and 1%, w/v). Soybean lecithin (1%, w/v) and Pluronic® F68 (0.5%, 1%, and 1.5%, w/v) were incorporated in the alcoholic and aqueous phases, respectively. The NPs were evaluated for particle size, zeta potential, entrapment efficiency percentage (EE%), morphological examination, drug release in simulated tear fluid (pH 7.4), Fourier-transform IR (FT-IR), X-ray diffraction (XRD), physical stability (2 months, 4°C and 25°C), and drug pharmacokinetics in the rabbit aqueous humor relative to an oily drug solution. Spherical, discrete NPs were successfully developed with mean particle size and zeta potential ranging from 73.29 to 320.15 nm and +20.51 to +40.32 mV, respectively. Higher EE% were achieved with Eudragit® RS100-based NPs. The duration of drug release was extended to more than 8 h. FT-IR and XRD revealed compatibility between inactive formulation ingredients and T HCl and permanence of the latter’s crystallinity, respectively. The NPs were physically stable, for at least 2 months, when refrigerated. F5-NP suspension significantly (P < 0.05) increased drug mean residence time and improved its ocular bioavailability; 1.657-fold.Key words: aqueous humor, chitosan, Eudragit® RS100, nanoparticles, terbinafine hydrochloride     

Treatment with atorvastatin is associated with a better prognosis in chronic heart failure with systolic dysfunction: results from The Daunia Heart Failure Registry

Background

Few works have evaluated the effect of statins on left ventricular dysfunction in patients with chronic heart failure (CHF), by using tissue Doppler imaging (TDI). We therefore aimed to investigate whether atorvastatin treatment may influence prognosis and myocardial performance evaluated by TDI in subjects with CHF.

Methods

Five hundred thirty-two consecutive CHF outpatients enrolled in a local registry, the Daunia Heart Failure Registry, were prospectively analysed. 195 patients with CHF and left ventricular ejection fraction (LVEF) ≤40 %, either in treatment with atorvastatin (N: 114) or without statins (N: 81), underwent TDI examination. Adverse events were evaluated during follow-up.

Results

The atorvastatin group showed a lower incidence of adverse events (cardiac death: 0 % vs 7 %, p < 0.01), and better TDI performance (E/E’ 15 ± 5.7 vs 18 ± 8.3, p < 001) than controls. Ischaemic CHF patients in treatment with atorvastatin also showed a lower incidence of adverse events (death: 10 % vs 26 %, p < 0.05; sustained ventricular arrhythmias: 5 % vs 19 %, p < 0.05, cardiac death: 0 vs 8 %, p < 0.05) and better TDI performance (E/E’ ratio: 15.00 ± 5.68 vs 19.72 ± 9.14, p < 0.01; St: 353.70 ± 48.96 vs 303.33 ± 68.52 msec, p < 0.01) than controls. The association between atorvastatin and lower rates of cardiac death remained statistically significant even after correction in a multivariable analysis (RR 0.83, 95 % CI 0.71–0.96, p < 0.05 in CHF with LVEF ≤40 %; RR 0.77, 95 % CI 0.62–0.95, p < 0.05 in ischaemic CHF with LVEF ≤40 %).

Conclusions

Treatment with atorvastatin in outpatients with systolic CHF is associated with fewer cardiac deaths, and a better left ventricular performance, as assessed by TDI.     

In vitro propagation of female Ephedra foliata Boiss. & Kotschy ex Boiss.: an endemic and threatened Gymnosperm of the Thar Desert

Ephedra foliata Boiss. & Kotschy ex Boiss., (family – Ephedraceae), is an ecologically and economically important threatened Gymnosperm of the Indian Thar Desert. A method for micropropagation of E. foliata using nodal explant of mature female plant has been developed. Maximum bud-break (90 %) of the explant was obtained on MS medium supplemented with 1.5 mg l⁻¹ of benzyl adenine (BA) + additives. Explant produces 5.3 ± 0.40 shoots from single node with 3.25 ± 0.29 cm length. The multiplication of shoots in culture was affected by salt composition of media, types and concentrations of plant growth regulators (PGR’s) and their interactions, time of transfer of the cultures. Maximum number of shoots (26.3 ± 0.82 per culture vessel) were regenerated on MS medium modified by reducing the concentration of nitrates to half supplemented with 200 mg l⁻¹ ammonium sulphate {(NH₄) ₂SO₄} (MMS3) + BA (0.25 mg l⁻¹), Kinetin (Kin; 0.25 mg l⁻¹), Indole-3-acetic acid (IAA; 0.1 mg l⁻¹) and additives. The in vitro produced shoots rooted under ex vitro on soilrite moistened with one-fourth strength of MS macro salts in screw cap bottles by treating the shoot base (s) with 500 mg l⁻¹ of Indole-3-butyric acid (IBA) for 5 min. The micropropagated plants were hardened in the green house. The described protocol can be applicable for (i) large scale plant production (ii) establishment of plants in natural habitat and (iii) germplasm conservation of this endemic Gymnosperm of arid regions.     

Salivary extracellular heat shock protein 70 (eHSP70) levels increase after 59 min of intense exercise and correlate with resting salivary secretory immunoglobulin A (SIgA) levels at rest

This study aimed to identify the response of a salivary stress protein, extracellular heat shock protein (eHSP70), to intense exercise and to investigate the relationship between salivary eHSP70 and salivary immunoglobulin A (SIgA) levels in response to exercise. Sixteen healthy sedentary young males (means ± SD 23.8 ± 1.5 years, 172.2 ± 6.4 cm, 68.3 ± 7.4 kg) performed 59 min of cycling exercise at 75 % VO2_max. Saliva and whole blood samples were collected before (Pre), immediately after (Post), and at 1, 2, 3, and 4 h after completion of the exercise (1, 2, 3, and 4 h). The salivary eHSP70 and SIgA levels were measured by enzyme-linked imunosorbent assay (ELISA), and the secretion rates were computed by multiplying the concentration by the saliva flow rate. White blood cells were analyzed using an automated cell counter with a direct-current detection system. The salivary eHSP70 secretion rates were 1.11 ± 0.86, 1.51 ± 1.47, 1.57 ± 1.32, 2.21 ± 2.04, 3.36 ± 2.72, and 6.89 ± 4.02 ng · min⁻¹ at Pre, Post, and 1, 2, 3, and 4 h, respectively. The salivary eHSP70 secretion rate was significantly higher at 4 h than that at Pre, Post, 1, and 3 h (p < 0.05). The SIgA secretion rates were 26.9 ± 12.6, 20.3 ± 10.4, 19.6 ± 11.0, 21.8 ± 12.8, 21.5 ± 11.9, and 21.9 ± 11.7 μg · min⁻¹ at Pre, Post, 1, 2, 3, and 4 h, respectively. The salivary SIgA secretion rate was significantly lower between 1 and 4 h than that at Pre (p < 0.05). There was a positive correlation between salivary eHSP70 and SIgA in both concentration and secretion rates before exercise (p < 0.05). The absolute number of white blood cells significantly increased after exercise, with a maximum at 2 h (p < 0.05). The neutrophil/lymphocyte ratio was significantly increased from 1 to 4 h when compared with that in the Pre samples (p < 0.05). The present study revealed that salivary eHSP70 significantly increased at 4 h after the 59 min of intense exercise in sedentary male subjects. Exercise stress can induce elevated salivary eHSP70 level and upregulate oral immune function partially.     

Dendrimer,Liposomes, Carbon Nanotubes and PLGA Nanoparticles: One Platform Assessment of Drug Delivery Potential

Liposomes (LIP), nanoparticles (NP), dendrimers (DEN), and carbon nanotubes (CNTs), represent eminent classes of drug delivery devices. A study was carried out herewith by employing docetaxel (DTX) as model drug to assess their comparative drug delivery potentials. Under optimized conditions, highest entrapment of DTX was observed in CNT-based formulation (DTX-CNTs, 74.70 ± 4.9%) followed by nanoparticles (DTX-NP, 62.34 ± 1.5%), liposome (49.2 ± 1.51%), and dendrimers (28.26 ± 1.74%). All the formulations were found to be of nanometric size. In vitro release studies were carried out in PBS (pH 7.0 and 4.0), wherein all the formulations showed biphasic release pattern. Cytotoxicity assay in human cervical cancer SiHa cells inferred lowest IC₅₀ value of 1,235.09 ± 41.93 nM with DTX-CNTs, followed by DTX-DEN, DTX-LIP, DTX-NP with IC₅₀ values of 1,571.22 ± 151.27, 1,653.98 ± 72.89, 1,922.75 ± 75.15 nM, respectively. Plain DTX showed higher hemolytic toxicity of 22.48 ± 0.94%, however loading of DTX inside nanocarriers drastically reduced its hemolytic toxicity (DTX-DEN, 17.22 ± 0.48%; DTX-LIP, 4.13 ± 0.19%; DTX-NP, 6.43 ± 0.44%; DTX-CNTs, 14.87 ± 1.69%).KEY WORDS: carbon nanotubes, dendrimer, drug delivery, liposomes, nanoparticles, nanotechnology     

Development and Characterization of Lyophilized Diazepam-Loaded Polymeric Micelles

Polymeric micelles were studied as delivery carriers of diazepam, a practically insoluble drug in water, for rectal administration. The diazepam-loaded polymeric micelles were developed by using poloxamer 407 (P407), poloxamer 188, and d-α-tocopheryl poly(ethylene glycol) 1000 succinate (TPGS). Among the used polymers, TPGS resulted in polymeric micelles with good characteristics for encapsulation of diazepam which had the small particle size of 8–12 nm and narrow size distribution (PI 0.053–0.275). Additionally, 7.5% w/v of TPGS could entirely entrap the desired concentration of diazepam (5 mg/mL). To improve the physical stability upon lyophilization, an addition of P407 of 1% w/v prevented aggregation, increased physical stability, and maintained chemical stability of the lyophilized powders of diazepam-loaded polymeric micelles for 3 months storage at 4°C. The rate and amount of diazepam release from TPGS polymeric micelles mainly depended on the concentration of TPGS. The release data were fitted to Higuchi''s model suggesting that the drug release mechanism was controlled by Fickian diffusion. In conclusion, 10% w/v TPGS and 1% w/v P407 were the optimum formulation of lyophilized diazepam-loaded polymeric micelles.Key words: diazepam, lyophilization, poloxamer 407, polymeric micelles, d-α-tocopheryl poly(ethylene glycol) 1000 succinate (TPGS)     

Temperature sensitivity of the low-moisture-content limit to negative seed longevity--moisture content relationships in hermetic storage

• Background and Aims The negative logarithmic relationship between orthodox seed longevity and moisture content in hermetic storage is subject to a low-moisture-content limit (m_c), but is m_c affected by temperature?• Methods Red clover (Trifolium pratense) and alfalfa (Medicago sativa) seeds were stored hermetically at 12 moisture contents (2–15 %) and five temperatures (–20, 30, 40, 50 and 65 °C) for up to 14·5 years, and loss in viability was estimated.• Key Results Viability did not change during 14·5 years hermetic storage at −20 °C with moisture contents from 2·2 to 14·9 % for red clover, or 2·0 to 12·0 % for alfalfa. Negative logarithmic relationships between longevity and moisture contents >m_c were detected at 30–65 °C, with discontinuities at low moisture contents; m_c varied between 4·0 and 5·4 % (red clover) or 4·2 and 5·5 % (alfalfa), depending upon storage temperature. Within the ranges investigated, a reduction in moisture content below m_c at any one temperature had no effect on longevity. Estimates of m_c were greater the cooler the temperature, the relationship (P < 0·01) being curvilinear. Above m_c, the estimates of C_H and C_Q (i.e. the temperature term of the seed viability equation) did not differ (P > 0·10) between species, whereas those of K_E and C_W did (P < 0·001).• Conclusions The low-moisture-content limit to negative logarithmic relationships between seed longevity and moisture content in hermetic storage increased the cooler the storage temperature, by approx. 1·5 % over 35 °C (4·0–4·2 % at 65 °C to 5·4–5·5 % at 30–40 °C) in these species. Further reduction in moisture content was not damaging. The variation in m_c implies greater sensitivity of longevity to temperature above, compared with below, m_c. This was confirmed (P < 0·005).     

Neurocardiological differences between musicians and control subjects

Background

Exercise training is beneficial in health and disease. Part of the training effect materialises in the brainstem due to the exercise-associated somatosensory nerve traffic. Because active music making also involves somatosensory nerve traffic, we hypothesised that this will have training effects resembling those of physical exercise.

Methods

We compared two groups of healthy, young subjects between 18 and 30 years: 25 music students (13/12 male/female, group M) and 28 controls (12/16 male/female, group C), peers, who were non-musicians. Measurement sessions to determine resting heart rate, resting blood pressure and baroreflex sensitivity (BRS) were held during morning hours.

Results

Groups M and C did not differ significantly in age (21.4 ± 3.0 vs 21.2 ± 3.1 years), height (1.79 ± 0.11 vs 1.77 ± 0.10 m), weight (68.0 ± 9.1 vs 66.8 ± 10.4 kg), body mass index (21.2 ± 2.5 vs 21.3 ± 2.4 kg∙m⁻²) and physical exercise volume (39.3 ± 38.8 vs 36.6 ± 23.6 metabolic equivalent hours/week). Group M practised music daily for 1.8 ± 0.7 h. In group M heart rate (65.1 ± 10.6 vs 68.8 ± 8.3 beats/min, trend P =0.08), systolic blood pressure (114.2 ± 8.7 vs 120.3 ± 10.0 mmHg, P = 0.01), diastolic blood pressure (65.0 ± 6.1 vs 71.0 ± 6.2 mmHg, P < 0.01) and mean blood pressure (83.7 ± 6.4 vs 89.4 ± 7.1, P < 0.01) were lower than in group C. BRS in groups M and C was 12.9 ± 6.7 and 11.3 ± 5.8 ms/mmHg, respectively (P = 0.17).

Conclusions

The results of our study suggest that active music making has training effects resembling those of physical exercise training. Our study opens a new perspective, in which active music making, additionally to being an artistic activity, renders concrete health benefits for the musician.     

Optimization of Storage and Manufacture Conditions for Imidapril Hydrochloride in Solid State as a Way to Reduce Costs of Antihypertensive Therapy

The effect of temperature and relative humidity (RH) on the stability of imidapril hydrochloride (IMD) in solid state was investigated. The main aim of this study was to determine the most appropriate conditions of storage and manufacture of IMD so that the efficiency of the technological process could be improved and its costs could be minimized. A reversed-phase high-performance liquid chromatography was validated and applied for the determination of IMD degradation samples under the following operating conditions: stationary phase, LiChrospher 100 RP-18 (size 5 μm) 250 × 4 mm I.D., and mobile phase, acetonitrile–methanol–phosphate buffer, pH 2.0, 0.035 mol L⁻¹ (60:10:30 v/v/v). The effect of temperature on IMD degradation rate was analyzed under increased RH ∼76.4% (within temperature range of 70–90°C) and decreased RH ∼0% (within temperature range of 90–110°C). The influence of RH was investigated under 90°C within RH range of 25.0–76.4%. IMD degradation accords with autocatalytic reaction model, and RH has no influence on its mechanism yet it increases its rate. The reaction also accelerates under high temperatures and in the presence of IMD degradation product. Pure IMD is more stable than other structurally related angiotensin-converting enzyme inhibitors, such as enalapril maleate, but it still should be stored in tightly closed containers and protected from moisture and high temperatures.KEY WORDS: angiotensin-converting enzyme inhibitors, imidapril hydrochloride, RP-HPLC, stability, thermodynamics     

Niosomal Gel of Lornoxicam for Topical Delivery: In vitro Assessment and Pharmacodynamic Activity

Lornoxicam is a potent oxicam class of non steroidal anti-inflammatory agent, prescribed for mild to moderate pain and inflammation. Niosomal gel of lornoxicam was developed for topical application. Lornoxicam niosomes (Lor-Nio) were fabricated by thin film hydration technique. Bilayer composition of niosomal vesicles was optimized. Lor-Nio dispersion was characterized by DSC, XRD, and FT-IR. Morphological evaluation was performed by scanning electron microscopy (SEM). Lor-Nio dispersion was incorporated into a gel using 2% w/w Carbopol 980 NF. Rheological and texture properties of Lor-Nio gel formulation showed suitability of the gel for topical application. The developed formulation was evaluated for in vitro skin permeation and skin deposition studies, occlusivity test and skin irritation studies. Pharmacodynamic activity of the Lor-Nio gel was performed by carragenan-induced rat paw model. Optimized Lor-Nio comprised of Span 60 and cholesterol in a molar ratio of 3:1 with 30 μM dicetyl palmitate as a stabilizer. It had particle size of 1.125 ± 0.212 μm (d₉₀), with entrapment efficiency of 52.38 ± 2.1%. DSC, XRD, and IR studies showed inclusion of Lor into niosomal vesicles. SEM studies showed spherical closed vesicular structure with particles in nanometer range. The in vitro skin permeation studies showed significant improvement in skin permeation and skin deposition for Lor-Nio gel (31.41 ± 2.24 μg/cm², 30.079 ± 1.2 μg/cm²) over plain lornoxicam gel (7.37 ± 1.27 μg/cm², 6.6 ± 2.52 μg/cm²). The Lor-Nio gel formulation showed enhanced anti-inflammatory activity by exhibiting mean edema inhibition (87.69 ± 1.43%) which was significantly more than the plain lornoxicam gel (53.84 ± 2.21%).KEY WORDS: anti-inflammatory activity, lornoxicam, niosomes, rheology, texture analysis     

Mixed Polyethylene Glycol-Modified Breviscapine-Loaded Solid Lipid Nanoparticles for Improved Brain Bioavailability: Preparation,Characterization, and In Vivo Cerebral Microdialysis Evaluation in Adult Sprague Dawley Rats

Breviscapine is used in the treatment of ischemic cerebrovascular diseases, but it has a low bioavailability in the brain due to its poor physicochemical properties and the activity of P-glycoprotein efflux pumps located at the blood–brain barrier. In the present study, breviscapine-loaded solid lipid nanoparticles (SLN) coated with polyethylene glycol (PEG) derivatives were formulated and evaluated for their ability to enhance brain bioavailability. The SLNs were either coated with polyethylene glycol (40) (PEG-40) stearate alone (Bre-GBSLN-PS) or a mixture of PEG-40 stearate and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-PEG2000 (DSPE-PEG₂₀₀₀) (Bre-GBSLN-PS-DSPE) and were characterized both in vitro and in vivo. The mean particle size, polydispersity index, and entrapment efficiency for Bre-GBSLN-PS and Bre-GBSLN-PS-DSPE were 21.60 ± 0.10 and 22.60 ± 0.70 nm, 0.27 ± 0.01 and 0.26 ± 0.04, and 46.89 ± 0.73% and 47.62 ± 1.86%, respectively. The brain pharmacokinetic parameters revealed that the brain bioavailability of breviscapine from the Bre-GBSLN-PS and Bre-GBSLN-PS-DSPE was significantly enhanced (p < 0.01) with the area under concentration–time curve (AUC) of 1.59 ± 0.39 and 1.42 ± 0.58 μg h/mL of breviscapine, respectively, in comparison to 0.11 ± 0.02 μg h/mL from the commercial breviscapine injection. The ratios of the brain AUC for scutellarin in comparison with the plasma scutellarin AUC for commercial breviscapine injection, Bre-GBSLN-PS, and Bre-GBSLN-PS-DSPE were 0.66%, 2.82%, and 4.51%, respectively. These results showed that though both SLN formulations increased brain uptake of breviscapine, Bre-GBSLN-PS-DSPE which was coated with a binary combination of PEG-40 stearate and DSPE-PEG₂₀₀₀ had a better brain bioavailability than Bre-GBSLN-PS. Thus, the coating of SLNs with the appropriate PEG derivative combination could improve brain bioavailability of breviscapine and can be a promising tool for brain drug delivery.KEY WORDS: breviscapine, microdialysis, mixed PEGylation, P-glycoprotein (P-gp), solid lipid nanoparticles     

Freeze-Dried Targeted Mannosylated Selenium-Loaded Nanoliposomes: Development and Evaluation

The aim of this investigation was to develop and evaluate freeze-dried mannosylated liposomes for the targeted delivery of selenium. Dipalmitoylphosphatidylcholine, distearoylphosphatidylglycerol, and cholesterol were dissolved in a chloroform and methanol mixture and allowed to form a thin film within a rotatory evaporator. This thin film was hydrated with a sodium selenite (5.8 μM) solution to form multilamellar vesicles and homogenized under high pressure to yield unilamellar nanoliposomes. Se-loaded nanoliposomes were mannosylated by 0.1% w/v mannosamine (Man-Lip-Se) prior to being lyophilized. Mannosamine concentration was optimized with cellular uptake studies in M receptor expressing cells. Non-lyophilized and lyophilized Man-Lip-Se were characterized for size, zeta potential, and entrapment efficiency. The influence of liposomal composition on the characteristics of Man-Lip-Se were evaluated using acidic and basic medium for 24 h. Thermal analysis and powder X-ray diffraction were used to determine the interaction of components within the Man-Lip-Se. The size, zeta potential and entrapment efficiency of the optimum Man-Lip-Se were observed to be 158 ± 28.9 nm, 33.21 ± 0.89 mV, and 77.27 ± 2.34%, respectively. An in vitro Se release of 70–75% up to 24 h in PBS pH 6.8 and <8% Se release in acidic media (0.1 N HCl) in 1 h was observed. The Man-Lip-Se were found to withstand gastric-like environments and showed sustained release. Stable freeze-dried Man-Lip-Se were successfully formulated with a size of <200 nm, ∼75% entrapment, and achieved controlled release of Se with stability under acidic media, which may be of importance in the targeted delivery of Se to the immune system.

Electronic supplementary material

The online version of this article (doi:10.1208/s12249-013-9988-3) contains supplementary material, which is available to authorized users.Key words: mannosylation, nanoliposome, selenium, thermal properties