Impact of Aluminum Oxide Nanocoating on Drug Release from Amorphous Solid Dispersion Particles.

Atomic layer coating (ALC) is emerging as a particle engineering strategy to inhibit surface crystallization of amorphous solid dispersions (ASDs). In this study, we turn our attention to evaluating drug release behavior from ALC-coated ASDs, and begin to develop a mechanistic framework. Posaconazole/hydroxypropyl methylcellulose acetate succinate was used as a model system at both 25% and 50% drug loadings. ALC-coatings of aluminum oxide up to 40 nm were evaluated for water sorption kinetics and dissolution performance under a range of pH conditions. Scanning electron microscopy with energy dispersive X-ray analysis was used to investigate the microstructure of partially released ASD particles. Coating thickness and defect density (inferred from deposition rates) were found to impact water sorption kinetics. Despite reduced water sorption kinetics, the presence of a coating was not found to impact dissolution rates under conditions where rapid drug release was observed. Under slower releasing conditions, underlying matrix crystallization was reduced by the coating, enabling greater levels of drug release. These results demonstrate that water was able to penetrate through the ALC coating, hydrating the amorphous solid, which can initiate dissolution of drug and/or polymer (depending on pH conditions). Swelling of the ASD substrate subsequently occurs, disrupting and cracking the coating, which serves to facilitate rapid drug release. Water sorption kinetics are highlighted as a potential predictive tool to investigate the coating quality and its potential impact on dissolution performance. This study has implications for formulation design and evaluation of ALC-coated ASD particles.

Atomic Layer Coating to Inhibit Surface Crystallization of Amorphous Pharmaceutical Powders.

Preventing crystallization is a primary concern when developing amorphous drug formulations. Recently, atomic layer coatings (ALCs) of aluminum oxide demonstrated crystallization inhibition of high drug loading amorphous solid dispersions (ASDs) for over 2 years. The goal of the current study was to probe the breadth and mechanisms of this exciting finding through multiple drug/polymer model systems, as well as particle and coating attributes. The model ASD systems selected provide for a range of hygroscopicity and chemical functional groups, which may contribute to the crystallization inhibition effect of the ALC coatings. Atomic layer coating was performed to apply a 5-25 nm layer of aluminum oxide or zinc oxide onto ASD particles, which imparted enhanced micromeritic properties, namely, reduced agglomeration and improved powder flowability. ASD particles were stored at 40 °C and a selected relative humidity level between 31 and 75%. Crystallization was monitored by X-ray powder diffraction and scanning electron microscopy (SEM) up to 48 weeks. Crystallization was observable by SEM within 1-2 weeks for all uncoated samples. After ALC, crystallization was effectively delayed or completely inhibited in some systems up to 48 weeks. The delay achieved was demonstrated regardless of polymer hygroscopicity, presence or absence of hydroxyl functional groups in drugs and/or polymers, particle size, or coating properties. The crystallization inhibition effect is attributed primarily to decreased surface molecular mobility. ALC has the potential to be a scalable strategy to enhance the physical stability of ASD systems to enable high drug loading and enhanced robustness to temperature or relative humidity excursions.

Surface nanocoating of high drug-loading spray-dried amorphous solid dispersions by atomic layer coating: Excellent physical stability under accelerated storage conditions for two years.

Physical instability remains a major concern with amorphous solid dispersions (ASDs). In addition to bulk crystallization inhibition, another potential strategy to improve the physical stability of ASDs is surface engineering. However, coating processes are extremely challenging for ASD microparticles. Herein, we describe for the first time the application of atomic layer coating (ALC), a solvent-free technique, to deposit a pinhole-free, ultra-thin film of aluminum oxide onto the surface of spray-dried ASD particles containing high drug loadings of ezetimibe with hydroxypropyl methylcellulose acetate succinate. ALC affords excellent control over the thickness, uniformity and conformality of the coating at the atomic scale. The freshly prepared coated ASD powders exhibited less agglomeration, a lower hygroscopicity, as well as improved wettability, flowability and compressibility compared to the uncoated samples. Under accelerated storage conditions, crystallization was detected in the uncoated 50% and 70% drug loading ASDs after only a few days, whereas the coated samples showed no evidence of physical instability for two years. Consequently, there was a dramatic decrease in the drug release from the uncoated ASDs during storage, while little change was observed for the coated samples. Using ALC for surface nanocoating of ASD paves the way for the development of higher drug loading ASD without compromising physical stability, thereby reducing the pill burden.

Clinicopathological Features and Therapeutic Responses of Chinese Patients with Advanced Lung Adenocarcinoma Harboring an Anaplastic Lymphoma Kinase Rearrangement.

BACKGROUND: Presence of anaplastic lymphoma kinase (ALK) rearrangement is an indication for crizotinib in the treatment of patients with advanced or metastatic lung adenocarcinoma. Here, we sought to elucidate the association between clinicopathological features and ALK rearrangement status in Chinese patients with advanced lung adenocarcinoma harboring an ALK rearrangement. PATIENTS AND METHODS: ALK rearrangement status was determined using immunohistochemistry (IHC) in tumor tissues from 120 patients with advanced lung adenocarcinoma, and further assessed by fluorescence in situ hybridization (FISH) assay. The associations between ALK rearrangement status and clinicopathological features were analyzed. RESULTS: According to IHC testing, the ALK-positive rate among the advanced lung adenocarcinoma patients was 6.67% (8/120). FISH validation found 5 patients with ALK rearrangement among the 8 IHC-positive cases. No significant difference was observed regarding age, sex, or smoking status between FISH-positive and -negative patients (p > 0.05). None of the 5 FISH-positive patients benefited from first-line chemotherapy. CONCLUSION: IHC can be used as a reliable method for ALK rearrangement screening in patients with lung adenocarcinoma, but further FISH validation is imperative. Presence of ALK rearrangement predicts a more aggressive biological behavior of the tumor and might be indicative of poor response to chemotherapy.

Cancer-related fatigue and chemotherapy-associated adverse effects: correlation with TNF-α, IL-1 and 17-hydroxycorticosteroids.

AIM: We sought to determine the relationship between cancer-related fatigue, chemotherapy-associated adverse effects in patients with advanced stages of cancer, and the levels of TNF-α, IL-1 and 17-hydroxycorticosteroids (17-HCS). PATIENTS & METHODS: Two hundred cancer patients were recruited. They were given a Cancer Fatigue Scale survey to assess their general state of health before and after chemotherapy. Their plasma levels of TNF-α and IL-1 and urine levels of 17-HCS were also measured. RESULTS: Increased levels of TNF-α and IL-1 are common in cancer patients. Thirty-five (17.5%) patients suffered from chemotherapy-associated adverse effects, but their plasma levels of TNF-α and IL-1 were not significantly elevated after chemotherapy. However, the urinary levels of 17-HCS levels were significantly elevated in 23 patients after chemotherapy. CONCLUSION: Patients who had elevated urinary levels of 17-HCS before chemotherapy are accompanied by chemotherapy-associated adverse effects. Thus, elevated 17-HCS in urine could be a possible predictor for chemotherapy-associated adverse effects.

Demethylzeylasteral exhibits dose-dependent inhibitory behaviour towards estradiol glucuronidation.

The disturbance of estradiol level might induce the occurence of some diseases, including cancer. Estradiol is mainly metabolized through the conjugation reactions, including the sulfation and glucuronidation reactions. The present study tried to evaluate the inhibition of estradiol glucuronidation by the major ingredients of Tripterygium wilfordii Hook F. demethylzeylasteral. Selective ion monitoring at negative ion mode ([M⁺ H⁻] = 447) was employed to monitor the two glucuronides of estradiol. The reaction rate was determined through comparison of peak area of these two glucuronides. Lineweaver-Burk plot and Dixon plot were utilized to determine the inhibition kinetic type, and the inhibition kinetic parameters (K i) were calculated using the second plot. Competitive inhibition of demethylzeylasteral towards the formation of two glucuronides of estradiol was demonstrated, and the K i values were calculated to be 453.3 and 110.9 µM, respectively. All these results will remind us the risk of elevated serum concentrations of estradiol due to the inhibition of estradiol glucuronidation by demethylzeylasteral.