The Acoustic Features of Inhalation can be Used to Quantify Aerosol Delivery from a Diskus™ Dry Powder Inhaler

Purpose

Some patients are unable to generate the peak inspiratory flow rate (PIFR) necessary to de-agglomerate drug particles from dry powder inhalers (DPIs). In this study we tested the hypothesis that the acoustic parameters of an inhalation are related to the PIFR and hence reflect drug delivery.

Methods

A sensitivity analysis of the relationship of the acoustics of inhalation to simultaneously recorded airflow, in a cohort of volunteers (n?=?92) was performed. The Next Generation Impactor (NGI) was used to assess in vitro drug delivery from salmeterol/fluticasone and salbutamol Diskus? DPIs. Fine particle fraction, FPF, (<5 μm) was measured at 30–90 l/min for 2–6 s and correlated with acoustically determined flow rate (IFRc). In pharmacokinetic studies using a salbutamol (200 μg) Diskus?, volunteers inhaled either at maximal or minimal effort on separate days.

Results

PIFRc was correlated with spirometrically determined values (R ²?=?0.88). In in vitro studies, FPF increased as both flow rate and inhalation duration increased for the salmeterol/fluticasone Diskus? (Adjusted R ²?=?0.95) and was proportional to flow rate only for the salbutamol Diskus? (Adjusted R ²?=?0.71). In pharmacokinetic studies, blood salbutamol levels measured at 20 min were significantly lower when PIFRc was less than 60 l/min, p?Conclusion Acoustically-determined PIFR is a suitable method for estimating drug delivery and for monitoring inhalation technique over time.     

Aerosolization,Drug Permeation and Cellular Interaction of Dry Powder Pulmonary Formulations of Corticosteroids with Hydroxypropyl-β-Cyclodextrin as a Solubilizer

Purpose

The purpose of this study was to assess the feasibility of hydroxypropyl-β-cyclodextrin as a solubilizer for the corticosteroids prednisolone and fludrocortisone acetate in dry powder inhalation formulations.

Methods

The dry particles were simultaneously produced and coated with nanosized L-leucine crystals using an aerosol flow reactor method. The aerosolization performances of carrier-free powders were studied using Easyhaler® and Twister? at 2 and 4 kPa pressure drops over the inhalers. Drug permeation properties of the formulations were tested across a Calu-3 cell monolayer. Toxicity and reactive oxygen species induction were tested against Calu-3 and A549 cell lines.

Results

The hydroxypropyl-β-cyclodextrin in the powders promoted the dissolution of fludrocortisone the most, followed by that of prednisolone. Fine particle fractions were 52–70% from emitted doses which showed good repeatability with a coefficient variation of 0.9–0.17. In addition, hydroxypropyl-β-cyclodextrin enhanced the permeation of the corticosteroids. The powders showed no statistically significant toxicity nor reactive oxygen species induction in the tested cell lines.

Conclusions

This study demonstrated the preparation and function of fine powder formulations which combine improved dissolution of poorly soluble drugs with good aerosolization performance. These results are expected to promote particle engineering as a way to develop new types of therapeutic pulmonary powders.

     

Effect of Microenvironmental pH Modulation on the Dissolution Rate and Oral Absorption of the Salt of a Weak Acid – Case Study of GDC-0810

Purpose

The purpose of this work is to investigate the effect of microenvironmental pH modulation on the in vitro dissolution rate and oral absorption of GDC-0810, an oral anti-cancer drug, in human.

Methods

The pH-solubility profile of GDC-0810 free acid and pH_max of its N-Methyl-D-glucamine (NMG) salt were determined. Precipitation studies were conducted for GDC-0810 NMG salt at different pH values. GDC-0810 200-mg dose NMG salt tablet formulations containing different levels of sodium bicarbonate as the pH modifier were tested for dissolution under the dual pH-dilution scheme. Three tablet formulations were evaluated in human as a part of a relative bioavailability study. A 200-mg dose of GDC-0810 was administered QD with low fat food.

Results

Intrinsic solubility of GDC-0810 free acid was found to be extremely low. The pH_max of the NMG salt suggested a strong tendency for form conversion to the free acid under GI conditions. In vitro dissolution profiles showed that the dissolution rate and extent of GDC-0810 increased with increasing the level of sodium bicarbonate in the formulation. The human PK data showed a similar trend for the geometric mean of C_max and AUC_0-t for formulations containing 5%, 10%, and 15% sodium bicarbonate, but the difference is not statistically significant.

Conclusion

Incorporation of a basic pH modifier, sodium bicarbonate, in GDC-0810 NMG salt tablet formulations enhanced in vitro dissolution rate of GDC-0810 via microenvironmental pH modulation. The human PK data showed no statistically significant difference in drug exposure from tablets containing 5%, 10%, and 15% sodium bicarbonate.

     

Impact of Study Design on the Evaluation of Inhaled and Intranasal Corticosteroids’ Effect on Hypothalamic-Pituitary-Adrenal Axis Function,Part I: General Overview of HPA Axis Study Design

Inhaled and intranasal corticosteroids (ICS and INS) are among the mainstays of the treatment for asthma and allergic rhinitis, respectively, and also carry the potential to suppress the hypothalamic-pituitary-adrenal (HPA) axis. Several important factors affect the interpretability of trials investigating the impact of ICS and INS on the HPA axis. This paper reviews 106 published clinical trials, peer-reviewed articles, and New Drug Application reviews of approved ICS and INS, using MEDLINE and Drugs@FDA database. The trials included in this review evaluated the potential impact on HPA axis function of eight approved single-ingredient ICS and INS (beclomethasone dipropionate, budesonide, ciclesonide, flunisolide, fluticasone furoate, flucticasone propionate, mometasone furoate, and triamcinolone acetonide) and combination products containing these ingredients. The most commonly utilized design was blinded, placebo controlled, and short term (< 6 weeks) for adult trials and blinded, placebo controlled, and long term (≥ 6 weeks) for pediatric trials. Factors potentially affecting trial results include the choice of dose, dosing duration, assay sensitivity, statistical methodology, and the study population evaluated (patients or healthy volunteers). All of these factors have the potential to affect the level of adrenal suppression detected. In conclusion, to be informative, a HPA axis study should be well designed and carefully implemented to minimize variability in results and improve the overall interpretability of data obtained.     

Dry Powder Coating of Pellets with Micronized Eudragit® RS for Extended Drug Release

PURPOSE: To develop a novel powder coating technology for extended-release pellets based on the acrylic polymer, Eudragit RS. METHODS: A mixture of micronized Eudragit RS plus talc and a liquid feed (plasticizer plus binder solution) were sprayed separately onto propranolol hydrochloride-loaded pellets in a fluidized bed coater. The coated pellets were heat-cured under different conditions (40 degrees C to 60 degrees C, 2 h to 24 h). The coalescence (film formation) of the polymer particles was studied via the determination of the glass transition and the minimum polymer-softening temperatures (MST). The coated pellets were characterized with respect to their morphologic, release, and stability properties. RESULTS: The optimum plasticizer type and concentration and process temperatures could be identified by the determination of the MST. High concentrations of plasticizer (40% based on the polymer) and a thermal treatment were necessary to achieve complete film formation and extended drug release. Curing the pellets resulted in release profiles, which did not change during storage for 3 years. The coated pellets had a smooth, continuous surface and a dense film structure after curing. CONCLUSIONS: This novel coating technique avoids the use of organic polymer solutions or latex dispersions, has short processing times, and results in stable extended-release profiles.     

Impact of Study Design on the Evaluation of Inhaled and Intranasal Corticosteroids' Effect on Hypothalamic–Pituitary–Adrenal Axis Function

In part I of this review, an overview of the designs of hypothalamic–pituitary–adrenal (HPA) axis studies in the setting of inhaled corticosteroids (ICS) or intranasal corticosteroids (INS) use was discussed. Part II provides detailed discussion on the HPA axis evaluation results for each common ICS and INS, and how these results are possibly affected by the factors of study design. Significant adrenal suppression at conventional ICS/INS doses appears to be rare in clinical settings. The magnitude of cortisol suppression varies widely among different study designs. Factors potentially impacting this variability include: the choice of dose, dosing duration, assay sensitivity, statistical methodology, study population, and compliance. All of these factors have the potential to affect the extent of HPA axis effects detected and should be considered when designing or interpreting the results of a HPA axis study. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2963–2979, 2014     

Human Serum Albumin as a Probe for Surface Conditioning—A Study of the Ageing Effect

Abstract

I¹²⁵ radiolabeled HSA (HSA-I¹²⁵) was utilised as a probe to quantify protein adsorption onto polystyrene (PS) and Poloxamine 908 coated PS (PS-908) particles. Upon ageing of the HSA-I¹²⁵ a dramatic increase in the amount of protein adsorbed onto the two particle systems was observed. This phenomenon was not due to lability of the protein-radionuclide bond and no modifications in the secondary structure of the native and radiolabelled protein could be identified which could explain this unusual ageing effect. Using the amount of protein adsorbed to the uncoated particles as a control for each time point, it was possible to reproducibily determine the amount of HSA adsorbed to the coated particles.     

Effect of the nutritional supplement ALAnerv® on the serum PON1 activity in post-acute stroke patients

BackgroundParaoxonase-1 (PON1) is one of the HDL-associated proteins which contributes to the antioxidant properties of these lipoproteins. The aim of this pilot study was to evaluate the effect of the nutritional supplement ALAnerv^® on serum PON1 activity in post-acute stroke patients undergoing rehabilitation.MethodsWe enrolled 28 post-acute stroke patients and randomly divided them into (–) ALAor (+) ALAstudy groups. All the patients underwent the same rehabilitation program and received comparable standard medications. Moreover, (+) ALA patients received ALAnerv^® for two weeks (2 pills/day). The serum PON1 activity was assessed on blood samples taken at the admission and at the discharge moments, respectively. We used paraoxon (paraoxonase activity, PONA), phenyl acetate (arylesterase activity, ARYLA) and dihydrocoumarin (lactonase activity, LACTA) as substrates, the latter activity being regarded as physiologically relevant. A control group of 14 apparently healthy subjects was also created.ResultsIn the (+) ALAgroup, LACTAsignificantly increased during the study period (17.6 ± 3.2 vs. 27.6 ± 3.5, p = 0.002). Moreover, the percentage of LACTAvariation between (–) ALAand (+) ALAgroups during the study was also statistically different (–11.7 ± 6.9% vs. +95.1 ± 29.7%, p < 0.0001).ConclusionsThese preliminary results suggest that ALAnerv^® could contribute to the improvement of the physiologically relevant LACTAof PON1 in post-acute stroke patients, enabling this enzyme to contribute to the redox correction. Also, this study raises the question about the effect of a longer treatment period over the other enzymatic activities of serum PON1.     

Azone® Decreases the Buccal Mucosal Permeation of Diazepam in a Concentration-Dependent Manner via a Reservoir Effect

The purpose of this study was to examine concentration-dependent effects of Azone® (AZ) on the buccal absorption of diazepam (DIAZ). Porcine buccal mucosa was placed in modified Ussing chambers and pretreated with 10 μL of 0%, 5%, 20%, and 50% (w/v) AZ in ethanol. DIAZ was administered to the donor chamber either in solution or a chitosan-based gel. The donor chamber disappearance, receptor chamber appearance, and tissue retention of DIAZ were monitored over 2 h by HPLC, with AZ tissue disposition also measured by liquid chromatography–mass spectrometry profiling of tissue cryosections. DIAZ steady-state flux values significantly (p < 0.05) decreased 1.4- and 2.4-fold in 20% and 50% AZ-pretreated tissues, respectively. Only 20% and 50% AZ-pretreated tissues were also accompanied by an increased loss of DIAZ from the donor chamber, suggesting DIAZ was forming a reservoir in the buccal mucosa with higher AZ concentrations. Indeed, the percentage of the initial DIAZ dose remaining in the mucosa following a 2 h experiment was increased 3.0-fold with a 50% AZ pretreatment compared with control. AZ provided a concentration-dependent reservoir for DIAZ in buccal mucosa, resulting in retarded release into the receptor chamber, an approach that may be exploited for controlled release of DIAZ. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:1133–1141, 2014     

Study on the Equivalent Conformation of Retinoids

具有诱导细胞分化作用及癌和皮肤病化学治疗作用的维甲类化合物，不仅要求分子一端有疏水性、另一端为极性羧基和整个分子的共轭性，而且分子的构象也起重要作用。本文合成的Ｎ（４羧基苯基）３，５双叔丁基４羟基苯甲酰胺（２）具有与全反式维甲酸（ＡＴＲＡ，１）相似性质的基团配置和构象，表现有维甲酸的生物活性。然而Ｎ甲基化合物３，由于构象的完全不同，丧失了活性。用Ｘ线晶体学、紫外和核磁共振等方法研究了化合物２、３和ＡＴＲＡ的结构异同。     

 Simulation Study on the Entrance of

d fund industries.The research indicates that the entrance of commercial banks into the property insurance and fund industries can increase their revenue and return per unit of risk,and significantly reduce their probability of bankruptcy.The results also indicate that appropriate proportion of nonbanking assets is indispensable for achieving the optimal effect of diversification.In addition,a comparative study shows that the simultaneous diversification into the property insurance and fund industries generates higher divers2;P<0.01)C与胰岛素水平、C反应蛋白、类风湿因子(RF)、肿胀指数、压痛指数、晨僵时间、病程、年龄、性别等无关;瘦素及瘦素受体在RA患者滑膜中的表达明显高于正常对照组。结论:瘦素可能通过在靶器官的高表达而起到调节炎症的作用;可能在炎性反应中参与急性时相蛋白的合成与调节而影响疾病的发展过程。     

Using a Serial Marker to Predict a Repeated Measures Outcome in a Cohort Design—Results of a Simulation Study

Abstract

Consider the cohort design and suppose that the outcome of primary interest is a continuous random variable observed repeatedly over time. Suppose that there is a second variable of clinical relevance which is also observed repeatedly. We are interested in assessing whether the “serial marker” is in some sense predictive of the primary outcome. We would also like to predict the trend for the primary outcome assuming that the clinical marker follows a profile of specific clinical interest. In series of earlier papers, we have addressed these issues by applying a bivariate repeated measures model. One regression model was prescribed to relate the primary outcome to important explanatory variables, while a second regression model was prescribed for the serial marker. In this paper, we perform a series of simulation studies to investigate the empirical properties of this approach. Bivariate repeated measures data were generated at random, and basic study parameters including the sample size, the number of time points, the degree of serial correlation within the clinical marker, and type of association between the serial marker and the primary outcome were varied. The ability of the methodology to capture the underlying relationship between the two set of repeated measures was assessed. The ability to predicting the primary outcome corresponding to a known marker profile of specific interest was examined.     

Effect of pH on Diclofenac Release from Eudragit RS100® Microparticles. A Kinetic Study by DSC

The present work is aimed at investigating the release of Diclofenac (DCF) from Eudragit RS100T® (RS) microparticles to a biological model membrane consisting of dimyristoylphosphatidylcholine (DMPC) multilamellar vesicles (MLV). The microparticles were prepared by the Quasi-Emulsion Solvent Diffusion method (QESD). The drug release was monitored by Differential Scanning Calorimetry (DSC) technique, following the effects exerted by DCF on the thermotropic behaviour of DMPC multilamellar vesicles at different temperatures. DCF affects the transition temperature (T_m) of phospholipid vesicles, causing a m shift towards lower values, which is modulated by the drug fraction entering into the lipid bilayer. Calorimetric measurements were performed at two different pH (4.0 and 7.4) on suspensions of blank liposomes added to weighed amounts of unloaded and DCF-loaded microspheres, as well as to the powdered free drug, after incubation at 37°C. The T_m shifts, caused by the drug released from the polymeric system or by the free drug during incubation cycles, were compared to those caused by a chosen molar fractions of the free drug dispersed directly in the membrane. This in vitro study suggests as the kinetic process involved in drug release is influenced by the amount of drug loaded in the microspheres as well as by the pH value, acting on drug solubility and membrane disorder.     

The Selection of a Pharmaceutical Salt—The Effect of the Acidity of the Counterion on Its Solubility and Potential Biopharmaceutical Performance

A roadmap for the selection of a pharmaceutical salt form for a development candidate is presented. The free base of the candidate did not have sufficient chemical stability for development. The initially selected salt form turned out to be undevelopable because it was unstable during scale-up synthesis and storage. The rationale for the new solid form screening and the criteria for selection are discussed. Before the final selection, the pH solubility profiles of the 2 new salts, a benzoate and a besylate, were compared. Atypical solubility behavior was observed for the benzoate salt in hydrochloric acid with and without normal saline. A scheme is proposed illustrating how the pKas of the counterion and active pharmaceutical ingredient, the medium composition, and final pH affect the solubility and solution equilibria of the 2 selected salt forms. This scheme also includes the equilibria between solution and solid phases in different pH ranges. The pharmaceutical importance of this research is that it sheds light on how the acidity of the counterion can affect the solubility of the selected salt form in the gastric environment. With a well-designed formulation strategy, this property potentially can be translated to optimal biopharmaceutical performance of the drug product.     

Pharmacokinetic-Pharmacodynamic Modelling of Morphine Transport Across the Blood-Brain Barrier as a Cause of the Antinociceptive Effect Delay in Rats—A Microdialysis Study

Purpose. To quantify the contribution of distributional processes across the blood-brain barrier (BBB) to the delay in antinociceptive effect of morphine in rats. Methods. Unbound morphine concentrations were monitored in venous blood and in brain extracellular fluid (ECF) using microdialysis (MD) and in arterial blood by regular sampling. Retrodialysis by drug was used for in vivo calibration of the MD probes. Morphine was infused (10 or 40 mg/kg) over 10 min intravenously. Nociception, measured by the electrical stimulation vocalisation method, and blood gas status were determined. Results. The half-life of unbound morphine in striatum was 44 min compared to 30 min in venous and arterial blood (p < 0.05). The BBB equilibration of morphine, expressed as the ratio of areas under the curve between striatum and venous blood, was less than unity (0.28 ± 0.09 and 0.22 ± 0.17 for 10 and 40 mg/kg), respectively, indicating active efflux of morphine across the BBB. The concentration-effect relationship exhibited a clear hysterisis with an effect delay half-life of 32 and 5 min based on arterial blood and brain ECF concentrations, respectively. Conclusions. Eighty five percent of the effect delay was caused by morphine transport across the BBB, indicating possible involvement of rate limiting mechanisms at the receptor level or distributional phenomena for the remaining effect delay of 5 min.     

Study on the metastable state of dilution of spectinomycin

The metastable state of dilution of spectinomycin has been studied by both induction period method and direct method.The polynuclear mechanism of lsing metastability has been disclosed,The metatable zone for dilution of spectinomycin was presented .The influence ofacetone concentraion and temperature on the metastability has been investigated.The induction period elongated as acetone concentraion increased and temperature decreasd The metastable zone-with was broadened with the decreasement of solubility,High superastruation level for nucleation indicated that spectinomycfin belongs to class I system.On the basis of classical nucleation theory the fundamental nucleation parameters for dilution have also been estimated,All the results were important for the control of industrial dilution of spectinomycin.     

Roll Compaction/Dry Granulation of Dibasic Calcium Phosphate Anhydrous—Does the Morphology of the Raw Material Influence the Tabletability of Dry Granules?

The influence of raw material particle morphology on the tabletabilty of dry granules was investigated. Therefore, dibasic calcium phosphate anhydrous was used as a model material. One milled grade, 2 agglomerated grades with different porosities, and a functionalized structure, that is, an agglomerate formed by very small primary particles, were included. Particle size, density, and specific surface area of raw materials were measured. The starting materials and 2 fractions of dry granules were compressed to tablets. The tabletability of granules was compared to that of the powders and the influence of specific compaction force, granule size, and lubrication on tablet tensile strength was evaluated. All materials showed a loss in tabletability induced by a previous compaction step but to a varying extent. Only in case of the functionalized calcium phosphate morphology, this effect depended on the specific compaction force. In contrast to the other materials, the tabletability of functionalized calcium phosphate was influenced by the granule size. This effect was not related to an overlubrication as internal and external lubrication resulted in similar tensile strengths. A clear influence of the particle morphology on tablet strength was demonstrated by the study. The functionalized structure showed aspects of a more plastic deformation behavior. The functionalized dibasic calcium phosphate and the more porous agglomerate performed as potential filler/binder in the field of roll compaction/dry granulation.     

The influence of azone® on the percutaneous absorption of methotrexate

The percutaneous absorption of the polar drug methotrexate has been examined in vitro. Two alcoholic gel formulations containing 1% methotrexate with or without Azone® were applied to full-thickness abdominal human skin mounted in all-glass Franz-type diffusion cells. In the absence of Azone® no percutaneous penetration of methotrexate was observed. In the presence of Azone® 190 ng/cm² permeated after 48 h. Azone® appears to be actingas an efficient penetration enhancer for this drug.