Publications by authors named "Jesper Ostergaard"

Article Synopsis
  • This study investigates how different ratios of excipients like lactose, microcrystalline cellulose, and dicalcium phosphate affect the swelling and drug release of propranolol hydrochloride (PPN) from polyethylene oxide (PEO) matrix compacts.
  • The researchers used microscopy to analyze the compact surfaces and conducted dissolution studies to assess how the excipient ratios influenced hydration rates and drug release dynamics.
  • Findings indicate that modifying the amount of PEO and the type or ratio of excipients can significantly affect drug release rates, highlighting the innovative use of UV dissolution imaging for optimizing formulations.
View Article and Find Full Text PDF

Biotherapeutics is the fastest growing class of drugs administered by subcutaneous injection. In vitro release testing mimicking physiological conditions at the injection site may guide formulation development and improve biopredictive capabilities. Here, anin vitrorelease cartridge (IVR cartridge) comprising a porous agarose matrix emulating subcutaneous tissue was explored.

View Article and Find Full Text PDF

The limitations inherent in conventional cancer treatment methods have stimulated recent efforts towards the design of safe nanomedicines with high efficacy for combating cancer through various promising approaches. A plethora of nanoparticles has been introduced in the development of cancer nanomedicines. Among them, different lipid nanoparticles are attractive for use due to numerous advantages and unique opportunities, including biocompatibility and targeted drug delivery.

View Article and Find Full Text PDF

The development of effective drug delivery systems remains a focus of extensive research to enhance therapeutic outcomes. Among these, in situ forming gels (ISG) have emerged as a promising avenue for controlled drug release. This research focuses on the mathematical modeling of levofloxacin HCl (Lv) release from zein-based ISG using the cup method, aiming to mimic the environment of a periodontal pocket.

View Article and Find Full Text PDF

Transport within human tissue matrices, e.g., the subcutaneous tissue, exhibits some resemblance to chromatographic processes.

View Article and Find Full Text PDF

In situ formation of high viscous inverse lyotropic non-lamellar liquid crystalline phases is a promising approach for sustained drug delivery in the joint. The in situ forming process on exposure of two diclofenac-loaded preformulations to aqueous media was characterized with respect to depot size and shape, initial release and structural transitions using UV-Vis imaging and spatially and time-resolved synchrotron small-angle X-ray scattering (SAXS). The preformulations consisted of 10 % (w/w) ethanol, 10 % (w/w) water and a binary lipid mixture of glycerol monooleate (GMO):1,2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DOPG) or GMO:medium chain triglycerides (MCT).

View Article and Find Full Text PDF
Article Synopsis
  • Analytical assessment of structural stability and integrity is crucial in developing therapeutic proteins, as it impacts drug efficacy and patient safety.
  • The study introduces a new method, Taylor dispersion analysis (TDA) with LED-UV fluorescence detection, which measures changes in protein size and intrinsic fluorescence during denaturation.
  • This method was used to evaluate the stability of therapeutic proteins like adalimumab and human serum albumin, showcasing a simple process that requires minimal sample size, making it suitable for early drug development stages.
View Article and Find Full Text PDF

A UV imaging release-testing setup comprising an agarose gel as a model for tumorous tissue was developed. The setup was optimized with respect to agarose concentration (0.5% (/)), injection procedure, and temperature control.

View Article and Find Full Text PDF
Article Synopsis
  • Biopharmaceuticals have transformed treatments for diseases like diabetes and cancer but can provoke immune responses that impact effectiveness and safety.
  • Current methods to assess these immune reactions are complicated and hinder effective patient monitoring.
  • The study introduces Flow Induced Dispersion Analysis (FIDA) as a new technique to reliably evaluate drug activity and immunogenicity, specifically using adalimumab in arthritis patients, with potential applications for various biopharmaceuticals.
View Article and Find Full Text PDF

In situ forming implants are exposed to an extracellular matrix resembling a gel rather than aqueous solution upon subcutaneous administration. The aim of study was to develop a gel-based release testing system for characterizing the long-term in vitro behavior of in situ forming implants. The gel-based system consisted of an agarose gel mimicking the subcutaneous injection site and a receiver layer comprising phosphate buffer.

View Article and Find Full Text PDF

UV-vis spectrometry is widely used in the pharmaceutical sciences for compound quantification, alone or in conjunction with separation techniques, due to most drug entities possessing a chromophore absorbing light in the range 190-800 nm. UV dissolution imaging, the scope of this review, generates spatially and temporally resolved absorbance maps by exploiting the UV absorbance of the analyte. This review aims to give an introduction to UV dissolution imaging and its use in the determination of intrinsic dissolution rates and drug release from whole dosage forms.

View Article and Find Full Text PDF

In the present study, a method for quantitation of the pharmaceutical peptide oxytocin (OT) and its diselenide-containing analogue (SeOT) in human plasma was developed using gradient elution LC-ICP-MS/MS. Plasma samples were precipitated with acetonitrile containing 1.0% TFA in a volume ratio of 1+3 (sample+precipitation agent) before analysis.

View Article and Find Full Text PDF

Formation of high viscous inverse lyotropic liquid crystalline phases in situ upon exposure of low viscous drug-loaded lipid preformulations to synovial fluid provides a promising approach for design of depot formulations for intra-articular drug delivery. Rational formulation design relies on a fundamental understanding of the synovial fluid-mediated dynamic structural transitions occurring at the administration site. At conditions mimicking the in vivo situation, we investigated in real-time such transitions at multiple positions by synchrotron small-angle X-ray scattering (SAXS) combined with an injection-cell.

View Article and Find Full Text PDF

Buccal films containing a pH modifying excipient may be able to increase bioavailability of drugs with pH-dependent solubility such as saquinavir. Access to suitable in vitro drug release testing methods may facilitate buccal formulation development. This study aimed to explore two release testing methods for characterising buccal films and to elucidate the relationship between microenvironmental pH (pH, i.

View Article and Find Full Text PDF
Article Synopsis
  • Understanding protein interactions is key for studying complex biomolecular processes and developing new biopharmaceutical therapies.
  • Current methods struggle to fully characterize these interactions due to limitations like surface immobilization and inability to mimic real biological conditions.
  • This study introduces flow induced dispersion analysis (FIDA) as a solution for in-solution characterization of protein interactions, demonstrating its effectiveness in analyzing the binding mechanism between TNF-α and adalimumab, including complex sizes and binding affinities.
View Article and Find Full Text PDF

Nanoparticles (NPs) are increasingly applied in research and development of new therapies. Characterization of NP systems most often include size, shape, size distribution, and charge but information on the chemical stability of NPs and investigation of the presence of dissolved species is most often missing in efficacy studies due to lack of appropriate methods. In this study, a method based on capillary electrophoresis coupled to inductively coupled plasma mass spectrometry (CE-ICP-MS) was established for analysis of selenium (Se) NPs and dissolved Se species in aqueous media.

View Article and Find Full Text PDF

The purpose of this study was to investigate whole-dosage form UV-vis imaging as a potential tool for functional characterization of excipients used in solid oral dosage forms. To this end, tablets (average mass 260.0 mg, 224.

View Article and Find Full Text PDF

The initial drug release from forming implants is affected by factors such as the physicochemical properties of the active pharmaceutical ingredient, the type of the excipients utilized, and the surrounding environment. The feasibility of UV-vis imaging for characterization of the initial behavior of poly(d,l-lactide--glycolide) (PLGA)/1-methyl-2-pyrrolidinone (NMP) forming implants was investigated. The release of leuprolide acetate (LA) and implant formation in real time were monitored using dual-wavelength imaging at 280 and 525 nm, respectively, in matrices based on agarose gel and hyaluronic acid (HA) solution emulating the subcutaneous matrix.

View Article and Find Full Text PDF

Co-amorphous systems comprising low-molecular weight drugs and co-formers constitute an interesting approach to optimize pharmaceutical performance of drugs with low aqueous solubility. Within the different types of co-amorphous systems, the combination of a drug with its own salt may be an attractive formulation option due the absence of any inactive co-formers. The aim of this study was to investigate the possibility of forming a co-amorphous system from naproxen (NAP) and its sodium salt (NAP(Na)).

View Article and Find Full Text PDF

Buccal delivery of saquinavir has the advantage to bypass the gastrointestinal enzymatic degradation and the hepatic first-pass metabolism. Saquinavir has a pH-dependent solubility and is poorly soluble in human saliva at the physiological pH. Decreasing microenvironmental pH (pH) in saliva may increase saquinavir release from buccal formulations.

View Article and Find Full Text PDF

Biopharmaceuticals such as protein and peptide-based drugs are often produced by fermentation processes where it is necessary to monitor the amount and quality of the product expressed during fermentation and for release testing of the final drug product. Standard procedures involve surface-based ligand binding technologies such as enzyme-linked immunosorbent assay and biolayer interferometry, or extensive purification using, e.g.

View Article and Find Full Text PDF

The purpose of this study was to conduct an interlaboratory ring-study, with six partners (academic and industrial), investigating the measurement of intrinsic dissolution rate (IDR) using surface dissolution imaging (SDI) equipment. Measurement of IDR is important in pharmaceutical research as it provides characterising information on drugs and their formulations. This work allowed us to assess the SDI's interlaboratory performance for measuring IDR using a defined standard operating procedure (see supporting information) and six drugs assigned as low (tadalafil, bromocriptine mesylate), medium (carvedilol, indomethacin) and high (ibuprofen, valsartan) solubility compounds.

View Article and Find Full Text PDF

Therapeutic proteins and peptides are mainly administrated by subcutaneous injection. In vitro release testing of subcutaneous injectables performed using methods that take the structure and environment of the subcutaneous tissue into account may improve predictability of the in vivo behavior and thereby facilitate establishment of in vitro in vivo correlations. The aim of the study was to develop a biopredictive flow-through in vitro release method with a gel-type matrix for subcutaneously administered formulations and to explore the possibility of establishing a level A in vitro in vivo correlation for selected insulin products.

View Article and Find Full Text PDF

Intra-articular depot injectables based on in situ suspension formation of ester prodrugs of nonsteroidal anti-inflammatory drugs are promising for management of joint pain. As candidates for this delivery approach, 5 diclofenac ester prodrugs comprising different imidazole-containing promoieties were synthesized and their physicochemical properties characterized. In vitro hydrolysis rates were investigated in buffer solutions, in 40% (v/v) human, equine, canine, and rat plasma, and in 80% (v/v) human and equine synovial fluid.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_session4pouihcm1mg888sikik8p1410f4rdbem): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once