AKT2 siRNA delivery with amphiphilic-based polymeric micelles show efficacy against cancer stem cells

Development of RNA interference-based therapies with appropriate therapeutic window remains a challenge for advanced cancers. Because cancer stem cells (CSC) are responsible of sustaining the metastatic spread of the disease to distal organs and the progressive gain of resistance of advanced cancers, new anticancer therapies should be validated specifically for this subpopulation of cells. A new amphihilic-based gene delivery system that combines Pluronic^® F127 micelles with polyplexes spontaneously formed by electrostatic interaction between anionic siRNA and cationic polyethylenimine (PEI) 10K, was designed (PM). Resultant PM gather the requirements for an efficient and safe transport of siRNA in terms of its physicochemical characteristics, internalization capacity, toxicity profile and silencing efficacy. PM were loaded with a siRNA against AKT2, an important oncogene involved in breast cancer tumorigenesis, with a special role in CSC malignancy. Efficacy of siAKT2-PM was validated in CSC isolated from two breast cancer cell lines: MCF-7 and Triple Negative MDA-MB-231 corresponding to an aggressive subtype of breast cancer. In both cases, we observed significant reduction on cell invasion capacity and strong inhibition of mammosphere formation after treatment. These results prompt AKT2 inhibition as a powerful therapeutic target against CSC and pave the way to the appearance of more effective nanomedicine-based gene therapies aimed to prevent CSC-related tumor recurrence.     

Interaction between the photosensitizer lumichrome and human serum albumin: effect of excipients

Lumichrome (Lc) is a photodegradation product of riboflavin that can be used as a photosensitizer (PS) in antibacterial photodynamic therapy (aPDT). The binding of Lc with plasma proteins such as human serum albumin (HSA) could affect its efficiency as PS. Excipients are necessary to prepare stable formulations to be used in aPDT and they may affect the PS-HSA binding. Hydroxypropyl (HP)-α, β, γ-cyclodextrin (CD), polyethylene glycol 400 (PEG400) and Pluronic^® F-127 (PF127) were selected as model excipients in this study. The intrinsic HSA fluorescence quenching and absorption and fluorescence spectroscopy were used to evaluate the Lc-HSA interaction in the absence and presence of excipients. Nano-differential scanning calorimetry (DSC) was used to determine the effect of excipients on HSA. The photostability of the samples was also evaluated. The combined results showed a modest interaction between Lc and HSA which was reduced mainly by HPβCD. No major alterations of the HSA nano-DSC thermogram were observed after addition of excipients. HSA did enhance Lc photodegradation. The presence of PF127 did also induce photochemical destabilization of Lc independent of HSA. In conclusion, HPαCD, HPγCD and PEG400 seemed to be the excipients more suitable for use in topical preparations containing Lc.     

Advances in nano-delivery systems for doxorubicin: an updated insight

Doxorubicin (DOX) is the most effective chemotherapeutic drug developed against broad range of cancers such as solid tumours, transplantable leukemias and lymphomas. Conventional DOX-induced cardiotoxicity has limited its use. FDA approved drugs i.e. non-pegylated liposomal (Myocet^®) and pegylated liposomal (Doxil^®) formulations have no doubt shown comparatively reduced cardiotoxicity, but has raised new toxicity issues. The entrapment of DOX in biocompatible, biodegradable and safe nano delivery systems can prevent its degradation in circulation minimising its toxicity with increased half-life, enhanced pharmacokinetic profile leading to improved patient compliance. In addition, nano delivery systems can actively and passively target the tumour resulting increase in therapeutic index and decreased side effects of drug. Foreseeing the need of a comprehensive review on DOX nanoformulations, in this article we for the first time have given an updated insight on DOX nano delivery systems.     

The use and safety of doxycycline hyclate and other second-generation tetracyclines

Tetracyclines have long been used to treat a wide variety of medical conditions, especially in the field of dermatology. Unfortunately, safety concerns, especially gastrointestinal (GI), have always been present. Other safety concerns have included tooth development in children, candidiasis, vestibular concerns, photosensitivity/phototoxicity, and more unusual adverse effects such as uncontrolled hypertension. This article first discusses the pharmacological development of the tetracyclines from the first to the second generation versions with an emphasis on the safety concerns, especially with regards to doxycycline hyclate (DH). Second, the adverse effects of the tetracyclines are discussed. Third, the favorable side effect profile of DH delayed release capsules (Doryx^®) is compared with DH powder contained in tablets (Vibramycin^®). Fourth, the increased use with a continued favorable safety profile is also discussed concerning the subantimicrobial dosing of DH for acne. Fifth, the safety of periodontic uses of DH is discussed. Last, the favorable safety profiles of the 2006 approved uses of an anti-inflammatory dose of 40 mg doxycycline for rosacea and an extended-release minocycline tablet for acne are also discussed.     

Paclitaxel-loaded PLGA nanoparticles surface modified with transferrin and Pluronic®P85, an in vitro cell line and in vivo biodistribution studies on rat model

The development of multidrug resistance (due to drug efflux by P-glycoproteins) is a major drawback with the use of paclitaxel (PTX) in the treatment of cancer. The rationale behind this study is to prepare PTX nanoparticles (NPs) for the reversal of multidrug resistance based on the fact that PTX loaded into NPs is not recognized by P-glycoproteins and hence is not effluxed out of the cell. Also, the intracellular penetration of the NPs could be enhanced by anchoring transferrin (Tf) on the PTX-PLGA-NPs. PTX-loaded PLGA NPs (PTX-PLGA-NPs), Pluronic^®P85-coated PLGA NPs (P85-PTX-PLGA-NPs), and Tf-anchored PLGA NPs (Tf-PTX-PLGA-NPs) were prepared and evaluted for cytotoxicity and intracellular uptake using C6 rat glioma cell line. A significant increase in cytotoxicity was observed in the order of Tf-PTX-PLGA-NPs > P85-PTX-PLGA-NPs > PTX-PLGA-NPs in comparison to drug solution. In vivo biodistribution on male Sprague–Dawley rats bearing C6 glioma (subcutaneous) showed higher tumor PTX concentrations in animals administered with PTX-NPs compared to drug solution.     

Morphine sulfate extended-release capsules for the treatment of chronic,moderate-to-severe pain

Background: Morphine sulfate extended-release capsules (KADIAN^®) contain polymer-coated morphine sulfate pellets that are formulated to deliver sustained plasma morphine levels with minimal fluctuation. Morphine sulfate extended-release capsules, the only opioid formulation indicated in the US for both once- and twice-daily (every 12 and every 24 h) dosing, is approved in eight dosage strengths and is effective against pain from diverse sources in a variety of patient types. The formulation of morphine sulfate extended-release capsules allows flexible dosing options: capsules can be taken whole or the contents can be sprinkled on apple sauce or delivered via a gastrostomy tube. Morphine sulfate extended-release capsules have no immediate-release component and no components that would limit high doses. Results/conclusion: The bioavailability of morphine sulfate extended-release capsules is not compromised when taken with food and dose dumping (immediate elevations in dose) does not occur when morphine sulfate extended-release capsules are taken concomitantly with alcohol. Nearly all patients taking morphine sulfate extended-release capsules for pain relief adhere to the recommended dosing frequency. The flexibility available with morphine sulfate extended-release capsules may offer clinical advantages for pain management.     

硝苯地平固体分散体胶囊剂的制备

目的:将难溶于水的硝苯地平(nifedipine,NF)制成聚乙二醇4000(PEG4000)固体分散体胶囊剂,以改善其溶出性能.方法:①溶剂(乙醇)-熔融法制备硝苯地平-PEG4000固体分散体,并添加适宜稀释剂尿素(或甘露醇、蔗糖、柠檬酸、β-环糊精)制成胶囊;②正交设计确定PEG4000、稀释剂最佳用量;③量热分析法、溶出度法验证NF固体分散体.结果:①正交设计确定了PEG4000、稀释剂尿素最佳用量,溶剂-熔融法制得NF固体分散体.②工艺是将NF超声分散于乙醇(体积质量比1:24)中,加入熔融(70℃)的PEG4000(与NF的质量比1:4)中,使均匀混合,添加尿素(与NF的质量比1:20),80℃挥去乙醇,填充胶囊.③样品DSC曲线中NF熔融峰(177℃)消失,PEG4000峰(66℃)前移;胶囊均重0.25 g,含NF 10 mg,溶出t0 525～35 min.结论:溶剂-熔融法成功制备NF固体分散体,NF溶出度显著增大;添加尿素填充胶囊不影响固体分散体的溶解性;工艺简单、易行、成本较低.     

Recent progress in the development of docetaxel and paclitaxel analogues

Docetaxel (Taxotere^®, Sanofi-Aventis) and paclitaxel (Taxol^®, Bristol-Myers Squibb) are potent anticancer agents commonly used for the treatment of breast, ovarian and other cancers. Chemotherapy with these compounds gives undesirable side effects due to their low solubility and to the lack of selectivity for cancer cells. Studies have been performed to solve these problems and to find more potent taxoids on drug-resistant cancers. This review summarises the progress in these areas as reported in recent patent applications on docetaxel and paclitaxel analogues that have been published between January 2003 and December 2005. The review specifically focuses on new methods for the production of taxoids, new potent analogues, including taxoid conjugates with improved solubility, tumour targeting taxoids and prodrugs, combinations with new anticancer agents and taxoid formulation and delivery.     

On the inherent properties of Soluplus and its application in ibuprofen solid dispersions generated by microwave-quench cooling technology

Abstract

Polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer, or Soluplus^®, is a relatively new copolymer and a promising carrier of amorphous solid dispersions. Knowledge on the inherent properties of Soluplus^® (e.g. cloud points, critical micelle concentrations, and viscosity) in different conditions is relatively inadequate, and the application characteristics of Soluplus^®-based solid dispersions made by microwave methods still need to be clarified. In the present investigation, the inherent properties of a Soluplus^® carrier, including cloud points, critical micelle concentrations, and viscosity, were explored in different media and in altered conditions. Ibuprofen, a BCS class II non-steroidal anti-inflammatory drug, was selected to develop Soluplus^®-based amorphous solid dispersions using the microwave-quench cooling (MQC) method. Scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Raman spectroscopy (RS), and Fourier transform infrared spectroscopy (FT-IR) were adopted to analyze amorphous properties and molecular interactions in ibuprofen/Soluplus^® amorphous solid dispersions generated by MQC. Dissolution, dissolution extension, phase solubility, equilibrium solubility, and supersaturated crystallization inhibiting experiments were performed to elucidate the effects of Soluplus^® on ibuprofen in solid dispersions. This research provides valuable information on the inherent properties of Soluplus^® and presents a basic understanding of Soluplus^® as a carrier of amorphous solid dispersions.     

Controlled release reservoir mini tablets approach for controlling the drug release of Galantamine Hydrobromide

The objective of this study is to explore and investigate the reservoir mini tablets approach to control the release of Galantamine Hydrobromide in comparison to desired release profile to the Innovator formulation Razadyne^® ER capsules as disclosed in US Patent 7,160,559 which is granted to Janseen Pharmaceutica NV. The core mini tablets were prepared using the direct compression and wet granulation methods. These core mini tablets were further coated with Galantamine Hydrobromide in two different portions; 70% as controlled release and 30% as immediate release and then filled in empty hard gelatin capsule shells. The dissolution profiles of each formulation were compared to those of Razadyne^® ER capsules and the mean dissolution time (MDT), dissolution efficiency (DE%) and dissolution similarity (f2 factor) were calculated. It was observed that core formulation plays an important role in controlling the drug release as well as maintaining pH independent drug release profile. The release mechanism of GAH from reservoir mini tablet formulation follows Higuchi and first order. These results imply that controlled release reservoir mini tablets which further filled into empty hard gelatin capsule shells can be a suitable method to formulate controlled release Galantamine hydrobromide.     

Intelligent hydrogels for the oral delivery of chemotherapeutics

A novel approach toward improvements of oral chemotherapeutic formulations has evolved, which combines solubilisation (molecular dispersion) of the hydrophobic anticancer drugs in micelles attached to large macromolecules or microparticles. The large size of the macromolecules or microgels prevents the gel components from being transported into the systemic circulation. The discussed gels comprise copolymers of poly(acrylic acid) (PAA) and Pluronic^® surfactants, linked via C–C bonds. The Pluronic-PAA copolymers are non-irritating when administered orally. The micelles formed in the Pluronic-PAA solutions and in crosslinked microgels can be loaded with chemotherapeutic drugs and then released in contact with the intestine. The microgels are collapsed at the acidic pH of the stomach and expand, thus releasing the loaded drugs at the pH of the lower gastrointestinal tract. Yet the microgels are mucoadhesive and enable longer retention time and prolonged release in the colon. Ease of preparation and formulation of the drugs with the Pluronic-PAA polymers and gels may enable the wider use of oral chemotherapy, resulting in a better patient compliance and improved quality of life of the patients.     

Sustained Delivery of Intact Drug to the Colon: Mesalamine Formulation and Temporal Gastrointestinal Transit Analysis

The goal was to use temporal gastrointestinal transit simulations and formulation to predict and provide sustained input of target-site directed oral drug delivery exclusively into the colon. Using mesalamine as the model drug for formulation coupled with stomach emptying rates (fed and unfed) plus intestinal transit times demonstrates concepts and provides a specific example for treatment in ulcerative colitis. Formulation involved extrusion and spheronization into beads which were then coated with aqueous Eudragit^® S. Drug is released only at colonic pH and gastrointestinal transit predicts sustained drug input into the colon, especially when food effects are included.     

Comparison of traditional and novel tableting excipients: Physical and compaction properties

Context: Novel tableting excipients are continuously developed and advertised with superior flow and compaction characteristics.

Objective: The objective of this study was to compare two traditionally used and two novel tableting excipients with regard to their physical and tableting properties as well as their magnesium stearate sensitivity. Avicel^® PH102 (microcrystalline cellulose) was compared to the novel co-processed excipient Prosolv^® SMCC90 (silicified microcrystalline cellulose), whereas Anhydrous Emcompress^® (anhydrous dicalcium phosphate) was compared to the novel spherically granulated excipient Fujicalin^® (anhydrous dicalcium phosphate).

Materials and methods: True density, particle size, specific surface area (SSA), flowability, tabletability, and magnesium stearate sensitivity of the excipients was determined.

Results and discussion: Due to the silification process (Prosolv^®) and the unique manufacturing process (Fujicalin^®), the novel excipients showed a comparably larger SSA. Hardest tablets by far could be obtained with Prosolv^®, followed by Avicel^® and Fujicalin^®. Avicel^® and Prosolv^® were sensitive to magnesium stearate, whereas Fujicalin^® and Emcompress^® did not show lubricant sensitivity. This confirms the plastic deformation behavior of microcrystalline cellulose and the brittle fracture of anhydrous dicalcium phosphate.

Conclusion: Compared to the traditional excipients the investigated novel tableting excipients were advantageous with regard to their SSA and their tableting properties.     

Characterization of nano oxaliplatin prepared by novel Fat Employing Supercritical Nano System,the FESNS®

Background: Oxaliplatin has long been used for the treatment of colorectal cancer via intra-venous infusion. In order to improve patient compliance, a solid dosage form for oral administration of oxaliplatin was prepared as nano-sized particles.

Method: Nano oxaliplatin was prepared employing Fat Employing Supercritical Nano System (FESNS^®) with Supercritical Fluid (SCF) apparatus by using myristyl alcohol as solvent. Morphology of nano oxaliplatin was examined by Scanning Electron Microscopy (SEM), and the particle size and zeta potential were confirmed with Dynamic Light Scattering (DLS). To characterize the nano oxaliplatin particles, solubility rate and in vitro efficacy study (MTS growth inhibition assay) were investigated compared to crude oxaliplatin as reference.

Result: FESNS^® provided reproducible nano oxaliplatin with high manufacturing yield (> 95%). SEM images showed that the particle size distribution of nano oxaliplatin ranged between 20 and 400?nm with the medium particle sizes (d₅₀) of about 164?nm determined by DLS. Pertaining to the long-term stability, no recrystallization of the nano oxaliplatin was observed with negative zeta potential in the state of solution. Nano oxaliplatin was completely dissolved within a couple of minutes in pH 4.0 and pH 6.8 buffer solutions while crude oxaliplatin took a couple of hours to go into solution. In case of MTS growth inhibition assay, the average concentration required to inhibit 50% of cell growth (GI₅₀) of nano oxaliplatin was decreased by about 45% in comparison to the crude oxaliplatin.

Conclusion: These results lead us to conclude that nano oxaliplatin would have a great potential for the improvement of efficacy and toxicity in human colorectal cancer treatment compared to the crude oxaliplatin.     

The pharmacokinetics of a long-acting OROS hydromorphone formulation

Importance of the field: New formulations of opiods can provide round-the-clock pain relief to improve pain management and quality of life for patients with chronic pain.

Areas covered in this review: Information and comments on the pharmacokinetic processes associated with a new once-daily formulation of the potent opiod hydromorphone.

What the reader will gain: This review presents an overview of data from several small pharmacokinetic studies to gain a better perspective on the pharmacokinetic properties of a new long-acting formulation of hydromorphone.

Take home message: The development of advanced oral formulation that deliver analgesic drugs over an extended period provides new solutions to improve pain management and quality of life for patients with chronic pain.     

Fabrication of Eudragit polymeric nanoparticles using ultrasonic nebulization method for enhanced oral absorption of megestrol acetate

Abstract

Megestrol acetate (MGA) is used as a progestagen to treat advanced cancers in the breast or uterus and anorexia-cachexia syndrome in cancer patients. Due to its low solubility (BCS class II), MGA bioavailability needs to be enhanced for efficacy and safety. We developed MGA-encapsulated Eudragit^® L100 (EUD) nanoparticles (MGA-EUD (1:1) and MGA-EUD (2:1)) using an ultrasonic nebulization method. MGA-EUD (1:1) and MGA-EUD (2:1) consisted of MGA and EUD at the mass ratios of 1:1 and 2:1. Their physicochemical properties, i.e. particle size, loading efficiency, morphology, and crystallinity were determined. Dissolution tests were performed using USP method II. For pharmacokinetics, they were orally administered at 50?mg/kg to mice. Microcrystalline MGA suspension (MGA-MC, Megace^®, BMS) was used as control. MGA-EUD (1:1) and MGA-EUD (2:1) had a smooth and spherical shape of 0.70 and 1.05?µm in diameter with loading efficiencies of 93 and 95% showing amorphous states of MGA. They significantly enhanced the dissolution potential of MGA. Oral bioavailability of MGA-EUD (1:1) and MGA-EUD (2:1) increased 2.0- and 1.7-fold compared to that of MGA-MC. It suggests that ultrasonic nebulization method for the fabrication of polymeric nanoparticles is a promising approach to improve the bioavailability of poorly soluble drugs.     

Evaluation of consistency for multiple experiments of a single combination in the time-dependence mixture toxicity assay

Test-to-test consistency was evaluated for a single binary combination of organic chemicals using an assay that examined toxicity over multiple exposure times. Six experiments were conducted. The toxicities of 3-chloro-2-butanone (3C2B), methyl crotonate (MC) and the mixture of both (MX) were evaluated in each experiment at 15, 30 and 45?min of exposure using the Microtox^® system. Concentration-response (x/y) curves were generated via the five-parameter logistic minus one-parameter (5PL???1P) curve-fitting function and were used to develop predicted x/y curves for the dose-addition (DA) and independence (I) models of combined effect. A variety of toxicity (e.g. effective concentration, EC₅₀) and time-dependent toxicity (TDT) endpoints, 5PL???1P parameters and various combined-effects metrics (e.g. MX/DA) were calculated. Test-to-test consistency was evaluated via the coefficient of variation (CV) or, for TDT, the standard deviation of mean values. In the study, CVs obtained for single-chemical and mixture toxicity endpoints (EC₂₅, EC₅₀ and EC₇₅) at each exposure time were?<20, as were those for the predicted DA and I curves. For the MX/DA metric, mixture toxicity was consistent with that predicted for DA at each exposure time in each experiment with CVs?<6, despite some substantial variation in TDT for MC-alone at the EC₂₅ and for the 30–45?min time-interval. There was a lower variation in TDT for 3C2B and MX. Mean and CV values for 5PL???1P-derived slope and asymmetry parameters were also assessed to provide bases for comparisons in future reports.     

Bupropion and naltrexone: a review of their use individually and in combination for the treatment of obesity

Background: Bupropion and naltrexone are centrally active drugs that have shown potential efficacy – alone and in combination – for the treatment of obesity. Objective: To explore the efficacy and safety of naltrexone and bupropion alone and in a novel combination drug that utilizes sustained-release (SR) formulations of both drugs and to evaluate their efficacy in promoting weight loss. The mechanisms of action of these centrally acting drugs are discussed. Preclinical and clinical studies of bupropion and naltrexone alone and in combination are reviewed. Results/conclusions: Both bupropion and naltrexone have been shown individually to induce weight loss. Bupropion has greater efficacy as monotherapy. Naltrexone SR potentiates the effects of bupropion SR; thus, this synergistic combination has the potential for additional weight loss compared to monotherapy. Current Phase III trials will yield further safety and efficacy information regarding these drugs in combination.     

Biotransformation of lignan glycoside to its aglycone by Woodfordia fruticosa flowers: quantification of compounds using a validated HPTLC method

Context: Saraca asoca Linn. (Caesalpiniaceae) is an important traditional remedy for gynaecological disorders and it contains lyoniside, an aryl tetralin lignan glycoside. The aglycone of lyoniside, lyoniresinol possesses structural similarity to enterolignan precursors which are established phytoestrogens.

Objectives: This work illustrates biotransformation of lyoniside to lyoniresinol using Woodfordia fruticosa Kurz. (Lythraceae) flowers and simultaneous quantification of lyoniside and lyoniresinol using a validated HPTLC method.

Materials and methods: The aqueous extract prepared from S. asoca bark was fermented using W. fruticosa flowers. The substrate and fermented product both were simultaneously analyzed using solvent system:toluene:ethyl acetate:formic acid (4:3:0.4) at 254?nm. The method was validated for specificity, accuracy, precision, linearity, sensitivity and robustness as per ICH guidelines.

Results: The substrate showed the presence of lyoniside, however, it decreased as the fermentation proceeded. On 3rd day, lyoniresinol starts appearing in the medium. In 8 days duration most of the lyoniside converted to lyoniresinol. The developed method was specific for lyoniside and lyoniresinol. Lyoniside and lyoniresinol showed linearity in the range of 250–3000 and 500–2500?ng. The method was accurate as resulted in 99.84% and 99.83% recovery, respectively, for lyoniside and lyoniresinol.

Conclusion: Aryl tetralin lignan glycoside, lyoniside was successfully transformed into lyoniresinol using W. fruticosa flowers and their contents were simultaneously analyzed using developed validated HPTLC method.