Development of modified-release tablets of zolpidem tartrate by biphasic quick/slow delivery system

Rectifying disorder of extracellular matrix to suppress urethral stricture by protein nanofilm-controlled drug delivery from urinary catheter

Urethral stricture secondary to urethral injury, afflicting both patients and urologists, is initiated by excessive deposition of extracellular matrix in the submucosal and periurethral tissues. Although various anti-fibrotic drugs have been applied to urethral stricture by irrigation or submucosal injection, their clinical feasibility and effectiveness are limited. Here, to target the pathological state of the extracellular matrix, we design a protein-based nanofilm-controlled drug delivery system and assemble it on the catheter. This approach, which integrates excellent anti-biofilm properties with stable and controlled drug delivery for tens of days in one step, ensures optimal efficacy and negligible side effects while preventing biofilm-related infections. In a rabbit model of urethral injury, the anti-fibrotic catheter maintains extracellular matrix homeostasis by reducing fibroblast-derived collagen production and enhancing metalloproteinase 1-induced collagen degradation, resulting in a greater improvement in lumen stenosis than other topical therapies for urethral stricture prevention. Such facilely fabricated biocompatible coating with antibacterial contamination and sustained-drug-release functionality could not only benefit populations at high risk of urethral stricture but also serve as an advanced paradigm for a range of biomedical applications.

Predicting Food Effects on Oral Extended-Release Drug Products: A Retrospective Evaluation

Theoretically, the risk of food effects for extended-release (ER) products compared to IR products may be less because: (1) postprandial physiological changes are usually transient and last for 2-3 h only; and (2) the percentage of drug release from an ER product within the first 2-3 h post dose is usually small under both fasted and fed states. The major postprandial physiological changes that can affect oral absorption of ER drugs are delayed gastric emptying and prolonged intestinal transit. Oral absorption of ER drugs under fasted state mainly occurs in large intestine (colon and rectum) while the absorption of ER drugs under fed state occurs in both small and large intestines. We hypothesized that food effects for ER products are mainly caused by intestinal region-dependent absorption and food intake is more likely to increase rather than decrease the exposure of ER products due to a longer transit time and improved absorption in small intestine. For drugs with good absorption from large intestine, food effects on the area under the curve (AUC) of ER products are usually not expected. Our survey of oral drugs approved by the US FDA between 1998-2021 identified 136 oral ER drug products. Among the 136 ER drug products, 31, 6 and 99 products exhibited increased, decreased, and unchanged AUC under fed conditions, respectively. In general, when an ER product exhibits a fasted bioavailability (BA) relative to its corresponding immediate-release (IR) product between 80-125%, regardless the solubility or permeability of drug substances, substantial food effects on the AUC of ER product are generally not expected. If the fasted relative BA data are not available, a high in vitro permeability (i.e., Caco-2 or MDCK cell permeability comparable or higher than that of metoprolol) may inform no food effect on the AUC of an ER product of high-solubility (BCS class I and III) drug.

Integration of lornoxicam nanocrystals into hydroxypropyl methylcellulose-based sustained release matrix to form a novel biphasic release system

The study aims to (a) enhance the solubility of a poorly soluble drug by optimization of nanocrystal formulation using the top-down approach and (b) modify the release profile of this drug, which exhibits a short elimination half-life, by the integration of a fast-release phase containing the optimized nanocrystals and a sustained-release phase in a compression-coated tablet. Nanocrystals of the model drug (lornoxicam; LNX) was prepared by simultaneous application of jet-milling and ball-milling techniques. Investigation of the precipitation inhibition capacity, thermal property, and interaction of different polymers with the drug revealed polyvinyl pyrrolidone K30 (PVP) as the most effective stabilizer for nanocrystals. The immediate-release layer containing the optimized nanocrystals (size of 279.5 ± 11.25 nm and polydispersity index of 0.204 ± 0.01) was then compressed on a zero-order sustained-release matrix core using different derivatives of hydroxypropyl methylcellulose (HPMC). Application of the Design of Experiment approach (DoE) was applied to optimize the formulation of tablet. Analysis of drug concentration in dog plasma by liquid chromatography-tandem mass spectrometry demonstrated an improvement in the release behavior of LNX from the optimal compression-coated tablet integrating a HPMC-based sustained release matrix core and a PVP-stabilized lornoxicam nanocrystals coating layer compared to the reference product.

Development of a 3D-Printed Dosing Platform to Aid in Zolpidem Withdrawal Therapy

The long-term use of benzodiazepine receptor agonists (BZRAs) is associated with multiple side effects, such as increased sedation, hangover or an elevated risk of dependency and abuse. Unfortunately, the long-term use of BZRAs is reaching worrying intake rates, and therefore, the need for action is high. It was demonstrated already that the overall willingness of patients for deprescription increased when a slow dose reduction scheme with the possibility for dose increase, if needed, is employed. The current study aims to develop a flexible dosing platform of zolpidem hemitartrate (ZHT) to facilitate such withdrawal therapy. As this is the first report on the extrusion and 3D printing of ZHT, its thermal behaviour and sensitivity towards photolytic degradation was characterised. It was shown that ZHT possesses multiple polymorphs and was especially prone to oxidative photolysis. Next, a variety of immediate release polymers (Eudragit EPO, Kollidon VA64, Kollidon 12PF and Soluplus) were blended and extruded with Polyox WSR N10 to investigate their feedability and printability by mechanical and rheological analysis. The addition of PEO was shown to enable printing of these brittle pharmaceutical polymers, although the processing temperature was deemed critical to avoid surface defects on the resulting filaments. An EPO(70)PEO(30) system was selected based on its suitable mechanical properties and low hygroscopicity favoring ZHT stability. The matrix was blended with 1% or 10% API. The effect of certain printing parameters (caplet size, nozzle diameter, % overlap) on dissolution behaviour and caplet weight/dimensions/quality was assessed. A flexible dosing platform capable of delivering <1 mg and up to 10 mg of ZHT was created. Either caplet modification (incorporation of channels) or disintegrant addition (Primojel, Explotab, Ac-Di-Sol, Primellose and Polyplasdone-XL) failed to achieve an immediate release profile. This study provides the first report of a 3D-printed flexible dosing platform containing ZHT to aid in withdrawal therapy.

Diltiazem-loaded electrospun nanofibers as a new wound dressing: fabrication, characterization, and experimental wound healing

Calcium channel blockers such as diltiazem have recently been investigated for their wound-healing potential. The aims of this study were to fabricate diltiazem-loaded nanofibers for a new wound dressing and investigate their beneficial properties for wound healing. Nanofibers were electrospun using polyvinyl alcohol solution containing 0, 2 or 4% diltiazem. Fibers were characterized in terms of physicochemical properties, drug release and fibroblast viability, and in animal wound healing assays. Compared to other formulations, nanofibers containing 4% diltiazem showed thin fiber size (152.7 nm), high porosity (88.4%), high swelling (110.4%), low water contact angle (29.1°) and little weight loss (17.3%). Drug release from 4%-diltiazem nanofibers showed good fit to a Korsmeyer-Peppas model, suggesting a non-Fickian release mechanism (R ² = 96%, n = 0.52). In vitro, 4%-diltiazem mats were not cytotoxic and enhanced fibroblast proliferation by 263% after 5 days of treatment compared to control. In vivo, wounds treated with this mat for 14 days showed the smallest size (14.7%) and better histopathologic characteristics compared to other wounds. The 4%-diltiazem mat also demonstrated significant antioxidant activity by reducing tissue MDA and nitrite levels by 63 and 59% compared to normal saline. The findings support the eligibility of this novel wound dressing for additional clinical research.

N-acetylcysteine-loaded electrospun mats improve wound healing in mice and human fibroblast proliferation in vitro: a potential application of nanotechnology in wound care

OBJECTIVES

N-acetylcysteine (NAC) has gained attention recently in dermatology as a unique anti-oxidant. In light of progress in nanotechnological methods, it was hypothesized that loading NAC onto nanofibers would positively affect skin wound healing. The objective of this study was to fabricate NAC-loaded electrospun mats and test their effect on wound healing in vivo and in vitro.

MATERIALS AND METHODS

Polyvinyl alcohol (PVA)-based mats loaded with NAC at three concentrations were electrospun and characterized in terms of physicochemical properties and drug release profile. Human fibroblast cells (in vitro) and mouse full-thickness skin wounds (in vivo) were treated with mats for 5 and 14 days, respectively. Wound area, tissue histopathology, fibroblast proliferation and cellular oxidative state were evaluated.

RESULTS

Mats containing 5% PVA/NAC showed thinner fibers with suitable physicochemical properties and a sustained drug release profile. PVA/NAC (5%) mats enhanced fibroblast proliferation and attachment in vitro. The mats resulted in significant wound closure with high levels of re-epithelialization and collagen fiber synthesis on day 14 post-surgery in vivo. The mats also reduced granulation tissue and edematous stroma to a higher extent. These findings were accompanied by a significant decrease in tissue lipid peroxidation and higher superoxide dismutase activity, which may explain how NAC improved wound healing.

CONCLUSION

We propose an NAC-loaded nanofibrous mat that takes the advantage of a porous nanoscaffold structure to release NAC in a sustained manner. This mat may be a promising candidate for further clinical evaluation.

Entrapment of Drugs within Metallic Platinum and Their Delivery

Platinum has been a widely used metal for a variety of implanted medical devices, because of its inertness, low corrosion rate, high biocompatibility, high electric conductivity, and good mechanical stability. A highly desirable property still in need to be addressed is the tailoring of drug-delivery ability to that metal. This is needed in order to treat infections due to the process of implanting, to treat postoperation pain, and to prevent blood clotting. Can Pt itself serve as a delivery matrix? A review on metallic implants (Lyndon, J. A.; Boyd, B. J.; Birbilis, N. Metallic implant drug/device combinations for controlled drug release in orthopaedic applications. J. Control. Release 2014, 179, 63-75) proposes that "Metals themselves can be used for delivering pharmaceutics" but adds that "there has been no current research into [that] possibility" despite its advantages. Here we present a solution to that challenge and show a new method of using an inert metal as a 3D matrix from within which entrapped drug molecules are released. This new type of drug-delivery system is fabricated by the methodolodgy of entrapment of molecules within metals, resulting in various drugs@Pt. Specifically the following drugs have been entrapped and released: the pain-killer and platelet-inhibitor nonsteroidal anti-inflammatory drugs (NSAIDs) ibuprofen and naproxen, the antibiotic ciprofloxacin, and the antiseptic chlorhexidine. The delivery profiles of all biocomposites were studied in two forms, powders and pressed discs, showing, in general, fast followed by slow first order release profiles. It is shown that the delivery kinetics can be tailored by changing the entrapment process, by applying different pressures in the disc preparation, and by changing the delivery temperature. The latter was also used to determine the activation energy for the release. Full characterization of the metallic biomaterials is provided, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDAX), thermogravimetric analysis (TGA), and surface area/porosity analysis.