The influence of vitamin E succinate on the stability of polyethylene oxide PEO controlled release matrix tablets

Stability of Abuse-deterrent properties of PEO-based Abuse-deterrent formulation

Abuse of opioid drug products is a national health crisis in the US. To deter abuse, a number of drug products with abuse-deterrent (AD) properties have been approved by the US Food and Drug Administration (FDA). For abuse deterrence, it is critical to maintain the AD properties during the product shelf life. However, no information on the stability of AD properties during product shelf life is publicly available. In this study, stability of AD properties of surrogate AD formulation (ADF) of opioid active pharmaceutical ingredients (APIs) were studied. Surrogate extended release (ER) AD tablets were prepared by direct compression using Diltiazem HCl (model drug), polyethylene oxide (PEO WSR 301) polymer and magnesium stearate followed by curing at 70 °C for 30 mins. The stability studies were conducted at 25 °C/60 % RH and 40 °C/75 % RH storage conditions for 12 months (M) and 6 months (M), respectively. In vitro characterization and evaluation of AD properties of tablets were performed. As anticipated, the curing process increased the crushing strength of the tablets. However, the tablets could still be manipulated and compromised leading to an enhancement in the amount of drug extracted in solvents (e.g., water, alcohol), regardless of extraction temperature as well as tablet storage condition and time. Furthermore, the granule particle size as well as viscosity in water of manipulated samples were found to be lower for tablets stored at 25 °C/60 % RH or 40 °C/75 % RH for 12 M or 3 M/6M, respectively. The changes in AD properties eased the syringeability of hydrated samples and ultimately led to the withdrawal of higher amounts of drug into the syringe, thereby, impacting the abuse deterrence potential of the formulation by an IV route. These data demonstrated that the stability of AD properties (i.e., granule particle size, viscosity and syringeability-injectability) of PEO-based tablets was dependent on the storage condition. In conclusion, the design of AD formulation and setting of product quality profile should take into consideration the stability of AD properties during the product shelf life.

Hot-Melt Extrusion: a Roadmap for Product Development

Hot-melt extrusion has found extensive application as a feasible pharmaceutical technological option over recent years. HME applications include solubility enhancement, taste masking, and sustained drug release. As bioavailability enhancement is a hot topic of today's science, one of the main applications of HME is centered on amorphous solid dispersions. This review describes the most significant aspects of HME technology and its use to prepare solid dispersions as a drug formulation strategy to enhance the solubility of poorly soluble drugs. It also addresses molecular and thermodynamic features critical for the physicochemical properties of these systems, mainly in what concerns miscibility and physical stability. Moreover, the importance of applying the Quality by Design philosophy in drug development is also discussed, as well as process analytical technologies in pharmaceutical HME monitoring, under the current standards of product development and regulatory guidance. Graphical Abstract.

Application of Focus Variation Microscopy and Dissolution Imaging in Understanding the Behaviour of Hydrophilic Matrices

Hydrophilic matrix systems can be found in a wide range of extended release pharmaceutical formulations. The main principle of these systems is that upon contact with water, the hydrophilic component swells to form a hydrated gel layer which controls drug release. The following work demonstrates an explorative study into the use of dissolution imaging and focus variation microscopy with hydrophilic polymers. This study investigated the surface properties of xanthan gum (XG), polyethylene oxide (PEO), and hypromellose (hydroxypropyl methylcellulose, HPMC) compacts with each of these three hydrophilic polymers from one of each classification of natural, semi-synthetic, or synthetic polymer using a focus variation instrument. The auto correlation length (Sal) showed all surface profiles from the compacts displayed a value below 0.1 mm, indicating that only high frequency components (i.e., roughness) were considered and that the analysis had been successful. The developed interfacial area ratio (Sdr) displayed values below 5% in line with ISO guidelines for all the polymers studied with their texture aspect ratio values (Str) > 0.5, indicating uniformity of the surfaces of the produced compacts. Of the various parameters studied, areal material ratio (Smr2) predicted XG to wet and hydrate quicker than PEO, with PEO also wetting and hydrating quicker than the HPMC. The dissolution imaging and initial swelling studies proved to concur with the findings from the areal material ratio (Smr2) parameter, suggesting porosity was not an indicator for the ease with which water ingress occurs. This study suggests the Smr2 surface parameter to potentially predict wetting and initial hydration of hydrophilic polymers, however care should be taken as this study consists of a selected number of hydrophilic polymers.

Drug release from magnesium aluminium silicate-polyethylene oxide (PEO) nanocomposite matrices: An investigation using the USP III apparatus

This work investigated the use of the USP III apparatus in discriminating simulated fed and fasted conditions as well as ionic strength on veegum-polyethylene (PEO) (called clay-PEO matrices hereafter) matrices. The successful formulations were characterised using differential scanning calorimetry (DSC) and evaluated for their physical properties. Isothermal calorimetry (ITC) was used to evaluate the thermodynamics of the complexation processes. The effect of agitation sequences on the matrices as evaluated from the USP III suggested an increase in polymer content to significantly decrease the burst release experienced using diltiazem hydrochloride (DILT) as a model cationic drug. The manufacturing methods showed superior performance in relation to a decrease in burst release over the physical manufactured counterparts. The clay-PEO matrices also showed robustness (no matrix failure) in up to 0.2 M ionic strength solutions mimicking the upper limit experienced in the GI tract. ITC results revealed that the binding between DILT and PEO was enthalpy and entropy-driven. Furthermore, the binding between veegum and DILT in the presence of PEO was shown to be enthalpy-driven and entropically unfavourable, which was also the case for the binding between veegum and PEO thus giving insights to how the matrices were performing on a molecular level.

Evaluation of the drug solubility and rush ageing on drug release performance of various model drugs from the modified release polyethylene oxide matrix tablets

Hydrophilic matrix systems are currently some of the most widely used drug delivery systems for controlled-release oral dosage forms. Amongst a variety of polymers, polyethylene oxide (PEO) is considered an important material used in pharmaceutical formulations. As PEO is sensitive to thermal oxidation, it is susceptible to free radical oxidative attack. The aim of this study was to investigate the stability of PEO based formulations containing different model drugs with different water solubility, namely propranolol HCl, theophylline and zonisamide. Both polyox matrices 750 and 303 grade were used as model carriers for the manufacture of tablets stored at 40 °C. The results of the present study suggest that the drug release from the matrix was affected by the length of storage conditions, solubility of drugs and the molecular weight of the polymers. Generally, increased drug release rates were prevalent in soluble drug formulations (propranolol) when stored at the elevated temperature (40 °C). In contrast, it was not observed with semi soluble (theophylline) and poorly soluble (zonisamide) drugs especially when formulated with PEO 303 polymer. This indicates that the main parameters controlling the drug release from fresh polyox matrices are the solubility of the drug in the dissolution medium and the molecular weight of the polymer. DSC traces indicated that that there was a big difference in the enthalpy and melting points of fresh and aged PEO samples containing propranolol, whereas the melting point of the aged polyox samples containing theophylline and zonisamide was unaffected.

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Stability and bioavailability of diltiazem/polyethylene oxide matrix tablets

The aim of this study was to prepare and evaluate in vitro and in vivo; Diltiazem-Hydrochloride (DTZ) in sustained-release matrix tablets. Stability of DTZ tablets prepared with polyethylene oxide (MWs 900 000, 4 000 000, and 8 000 000) with or without addition of electrolytes was carried-out for 1-month, under short-term storage at 40 °C/75% RH. Stability was evaluated by DTZ content, DSC and drug release using the Flow-Through Cell (USP # IV). The majority of stored tablets were stable for 1-month under short-term storage with respect to DTZ content and drug release. DSC curves of stored samples showed appearance of new exothermic peak after 1-month storage at 40 °C/75% RH, which was not observed after 5 years storage at room temperature. A selected formula was tested in vivo against reference product on eight healthy human volunteers. DTZ-plasma profiles were different between the two formulae. However, no statistically significant differences were detected between C_max, AUC_0-48 and AUC_0-∞. The two products were therapeutically in-equivalent, as 90% confidence intervals "T/R" were 88.82-205.76, 91.40-139.94, and 93.73-134.97 for C_max, AUC_0-48 and AUC_0-∞, respectively. This study highlighted possible differences observed between the two regimes frequently applied for stability testing.

To postpone the precipitation of manganese oxides in the degradation of tetrachloroethylene by controlling the permanganate concentration

Controlled-release permanganate (CRP) is a relatively new technology used to treat contaminated groundwater. This study tested the encapsulation of permanganate using stearic acid to realize controlled-release properties. Batch experiments were conducted to investigate the performance of manganese oxides (MnO₂) in the reaction between CRP and the contaminant of interest: tetrachloroethylene (PCE). The results showed that higher ionic strengths (I = 0.1 mol/L) cause earlier precipitation of MnO₂ colloids. Using CRP to degrade PCE could decrease the amount of MnO₂ colloids produced and postpone precipitation compared to raw potassium permanganate (KMnO₄) under high ionic strength conditions by controlling the KMnO₄ concentration in the solution. The amount of MnO₂ colloids produced and the time of precipitation depended more on the CRP grain size than on the CRP mass ratio. Controlling the KMnO₄ concentration used in the reaction could control the formation of MnO₂ precipitates in the premise of guarantee the removal rate of PCE.

Electrospun Contrast-Agent-Loaded Fibers for Colon-Targeted MRI

Magnetic resonance imaging is a diagnostic tool used for detecting abnormal organs and tissues, often using Gd(III) complexes as contrast-enhancing agents. In this work, core-shell polymer fibers have been prepared using coaxial electrospinning, with the intent of delivering gadolinium (III) diethylenetriaminepentaacetate hydrate (Gd(DTPA)) selectively to the colon. The fibers comprise a poly(ethylene oxide) (PEO) core loaded with Gd(DTPA), and a Eudragit S100 shell. They are homogeneous, with distinct core-shell phases. The components in the fibers are dispersed in an amorphous fashion. The proton relaxivities of Gd(DTPA) are preserved after electrospinning. To permit easy visualization of the release of the active ingredient from the fibers, analogous materials are prepared loaded with the dye rhodamine B. Very little release is seen in a pH 1.0 buffer, while sustained release is seen at pH 7.4. The fibers thus have the potential to selectively deliver Gd(DTPA) to the colon. Mucoadhesion studies reveal there are strong adhesive forces between porcine colon mucosa and PEO from the core, and the dye-loaded fibers can be successfully used to image the porcine colon wall. The electrospun core-shell fibers prepared in this work can thus be developed as advanced functional materials for effective imaging of colonic abnormalities.

Comparative evaluation of drug release from aged prolonged polyethylene oxide tablet matrices: effect of excipient and drug type

Polyethylene oxide (PEO) undergoes structural adjustments caused by elevated temperatures, which results in loss of its stability within direct compression tablets. The aim of this study was to evaluate the influence of filler solubility on the drug delivery process of matrix tablets containing drugs with different water-solubility properties and stored at elevated temperature. The results demonstrated that in the case of propranolol HCl (highly water-soluble) tablet matrices, soluble lactose promoted drug release, whereas, a stable release of drug was observed with insoluble DCP. A drug release pattern similar to the propranolol HCl formulation containing DCP was obtained for hydrophilic matrix tablets containing either lactose or DCP for the less water-soluble drug, zonisamide. In the case of the partially water-soluble drug, theophylline, formulated with lower molecular weight PEO 750, drug release increased considerably in the presence of both fillers with increasing storage time, however a stable release rate (similar to fresh samples) was observed in the case of higher molecular weight PEO 303 tablet matrices containing theophylline with either lactose or DCP. The hydration properties (e.g. solubility) of the diluents had a considerable effect on drug release behavior from various model matrices; this effect was dependent on both molecular weight of PEO and solubility of drug.

Development of KMnO(4)-releasing composites for in situ chemical oxidation of TCE-contaminated groundwater

The objective of this study was to develop a controlled-oxidant-release technology combining in situ chemical oxidation (ISCO) and permeable reactive barrier (PRB) concepts to remediate trichloroethene (TCE)-contaminated groundwater. In this study, a potassium permanganate (KMnO4)-releasing composite (PRC) was designed for KMnO4 release. The components of this PRC included polycaprolactone (PCL), KMnO4, and starch with a weight ratio of 1.14:2:0.96. Approximately 64% (w/w) of the KMnO4 was released from the PRC after 76 days of operation in a batch system. The results indicate that the released KMnO4 could oxidize TCE effectively. The results from a column study show that the KMnO4 released from 200 g of PRC could effectively remediate 101 pore volumes (PV) of TCE-contaminated groundwater (initial TCE concentration = 0.5 mg/L) and achieve up to 95% TCE removal. The effectiveness of the PRC system was verified by the following characteristics of the effluents collected after the PRC columns (barrier): (1) decreased TCE concentrations, (2) increased ORP and pH values, and (3) increased MnO2 and KMnO4 concentrations. The results of environmental scanning electron microscope (ESEM) analysis show that the PCL and starch completely filled up the pore spaces of the PRC, creating a composite with low porosity. Secondary micro-scale capillary permeability causes the KMnO4 release, mainly through a reaction-diffusion mechanism. The PRC developed could be used as an ISCO-based passive barrier system for plume control, and it has the potential to become a cost-effective alternative for the remediation of chlorinated solvent-contaminated groundwater.