Browsing by Subject "Drug release"

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  • Paukkonen, Heli; Ukkonen, Anni; Szilvay, Geza; Yliperttula, Marjo; Laaksonen, Timo (2017)
    The purpose of this study was to construct biopolymer-based oil-in-water emulsion formulations for encapsulation and release of poorly water soluble model compounds naproxen and ibuprofen. Class II hydrophobin protein HFBII from Trichoderma reesei was used as a surfactant to stabilize the oil/water interfaces of the emulsion droplets in the continuous aqueous phase. Nanofibrillated cellulose (NFC) was used as a viscosity modifier to further stabilize the emulsions and encapsulate protein coated oil droplets in NFC fiber network. The potential of both native and oxidized NFC were studied for this purpose. Various emulsion formulations were prepared and the abilities of different formulations to control the drug release rate of naproxen and ibuprofen, used as model compounds, were evaluated. The optimal formulation for sustained drug release consisted of 0.01% of drug, 0.1% HFBII, 0.15% oxidized NFC, 10% soybean oil and 90% water phase. By comparison, the use of native NFC in combination with HFBII resulted in an immediate drug release for both of the compounds. The results indicate that these NFC originated biopolymers are suitable for pharmaceutical emulsion formulations. The native and oxidized NFC grades can be used as emulsion stabilizers in sustained and immediate drug release applications. Furthermore, stabilization of the emulsions was achieved with low concentrations of both HFBII and NFC, which may be an advantage when compared to surfactant concentrations of conventional excipients traditionally used in pharmaceutical emulsion formulations. (C) 2017 Elsevier B.V. All rights reserved.
  • Pessi, Jenni; Svanbäck, Sami; Lassila, Ilkka; Haeggstrom, Edward; Yliruusi, Jouko (2017)
    We introduce a system with a lyophilic matrix to aid dissolution studies of powders and particulate systems. This lyophilic matrix method (LM method) is based on the ability to discriminate between non-dissolved particles and the dissolved species. In the LM method the test substance is embedded in a thin lyophilic core-shell matrix. This permits rapid contact with the dissolution medium while minimizing dispersion of non-dissolved particles without presenting a substantial diffusion barrier. The method produces realistic dissolution and release results for particulate systems, especially those featuring nanoscale particles. By minimizing method-induced effects on the dissolution profile of nanopowders, the LM method overcomes shortcomings associated with current dissolution tests. (C) 2017 Elsevier B.V. All rights reserved.
  • Paukkonen, Heli; Kunnari, Mikko; Lauren, Patrick; Hakkarainen, Tiina; Auvinen, Vili-Veli; Oksanen, Timo; Koivuniemi, Raili; Yliperttula, Marjo; Laaksonen, Timo (2017)
    Concentrated 3% and 6.5% anionic nanofibrillar cellulose (ANFC) hydrogels were introduced as matrix reservoirs for controlled delivery applications of small molecules and proteins. A further aim was to study how the freeze-drying and subsequent rehydration of ANFC hydrogel affects the rheological properties and drug release of selected model compounds from the reconstructed hydrogels. It was demonstrated that the 3% and 6.5% ANFC hydrogels can be freeze-dried with suitable excipients into highly porous aerogel structures and redispersed back into the hydrogel form without significant change in the rheological properties. Freeze-drying did not affect the drug release properties from redispersed ANFC hydrogels, indicating that these systems could be stored in the dry form and only redispersed when needed. For large molecules, the diffusion coefficients were significantly smaller when higher ANFC fiber content was used, indicating that the amount of ANFC fibers in the hydrogel can be used to control the release rate. The release of small molecules was controlled with the ANFC fiber content only to a moderate extent. The results indicate that ANFC hydrogel can be used for controlled delivery of several types of molecules and that the hydrogel can be successfully freeze-dried and redispersed.
  • Peltonen, Leena (2018)
    The number of poorly soluble drug candidates is increasing, and this is also seen in the research interest towards drug nanoparticles and (nano-)cocrystals; improved solubility is the most important application of these nanosystems. In order to confirm the functionality of these nanoparticles throughout their lifecycle, repeatability of the formulation processes, functional performance of the formed systems in pre-determined way and system stability, a thorough physicochemical understanding with the aid of necessary analytical techniques is needed. Even very minor deviations in for example particle size or size deviation in nanoscale can alter the product bioavailability, and the effect is even more dramatic with the smallest particle size fractions. Also, small particle size sets special requirements for the analytical techniques. In this review most important physicochemical properties of drug nanocrystals and nano-cocrystals are presented, suitable analytical techniques, their pros and cons, are described with the extra input on practical point of view.
  • Chen, Lu; Zhang, Liucheng; Zhang, Hongbo; Sun, Xiaoming; Liu, Dan; Zhang, Jianming; Zhang, Yuguang; Cheng, Liying; Santos, Hélder A.; Cui, Wenguo (2021)
    Immune cells play a crucial regulatory role in inflammatory phase and proliferative phase during skin healing. How to programmatically activate sequential immune responses is the key for scarless skin regeneration. In this study, an “Inner-Outer” IL-10-loaded electrospun fiber with cascade release behavior was constructed. During the inflammatory phase, the electrospun fiber released a lower concentration of IL-10 within the wound, inhibiting excessive recruitment of inflammatory cells and polarizing macrophages into anti-inflammatory phenotype “M2c” to suppress excessive inflammation response. During the proliferative phase, a higher concentration of IL-10 released by the fiber and the anti-fibrotic cytokines secreted by polarized “M2c” directly acted on dermal fibroblasts to simultaneously inhibit extracellular matrix overdeposition and promote fibroblast migration. The “Inner-Outer” IL-10-loaded electrospun fiber programmatically activated the sequential immune responses during wound healing and led to scarless skin regeneration, which is a promising immunomodulatory biomaterial with great potential for promoting complete tissue regeneration.
  • Kääriäinen, Tommi Olavi; Kemell, Marianna Leena; Vehkamäki, Marko Juhani; Kääriäinen, Marja-Leena; Correia, Alexandra; Almeida Santos, Helder; Marques dos Santos Bimbo, Luis Maria; Hirvonen, Jouni Tapio; Hoppu, Pekka; George, Steven M.; Cameron, David C.; Ritala, Mikko Kalervo; Leskelä, Markku Antero (2017)
    Organic solid pharmaceutical powders are used for the preparation of various drug dosage forms. Primary particles in powder form undergo several processing steps first in pharmaceutical formulations followed by pharmaceutical manufacturing to final dosage form of a drug. These unit operations involve both handling of powders in aqueous or solvent solutions and drying. There will be a probable rise for a demand for the different unit operations in the requirements of protecting the active pharmaceutical ingredient or challenges in powder handling. Besides pharmaceutical manufacturing, there are many biological interfaces where control of surface characteristics of pharmaceutical powders can improve the therapeutic response and bioavailability. In this work, we have modified acetaminophen particles with atomic layer deposition (ALD) by conformal nanometer scale coatings in a one-step coating process. According to the results, ALD comprising common chemistries for Al2O3, TiO2 and ZnO is shown to be a promising coating method for solid pharmaceutical powders. Acetaminophen does not undergo degradation during the ALD coating and maintains its stable polymorphic structure. The nanometer scale ALD coating can sustain the drug release. ALD oxide coated acetaminophen particles show different cytocompatibility assessed in in vitro intestinal Caco-2 cells.
  • Lauren, Patrick; Lou, Yan-Ru; Raki, Mari; Urtti, Arto; Bergström, Kim; Yliperttula, Marjo (2014)
  • Nurmi, Riikka (Helsingfors universitet, 2017)
    Liposomes are spherical nano-sized drug delivery systems which are composed of lipid bilayer. With liposomes drugs can be targeted for example to tumours and targeting can be passive or active. Drug release from liposomes can also be activated by different methods. Light is very promising triggering method, because it enables drug release at specific time and site. This study examined light activated indocyanine green (ICG) liposomes. Drug release from liposomes happens because ICG converts light energy to heat. ICG is clinically approved imaging agent, so ICG liposomes are very promising drug delivery systems even for clinical use. Liposomes were prepared by thin-film hydration method. One aim of the study was to prepare as small ICG-liposomes as possible. The bigger 100 nm liposomes were studied in three different formulations and the purpose was to find differences between those formulations. In formulation A ICG was in PEGs, in formulation B ICG was in lipid bilayer with no PEGs and in formulation C ICG was supposed to be in lipid bilayer although the formulation C included PEGs. In this study, the cell up take of ICG liposomes was studied with pharmacokinetic model and data from in vitro studies was supposed to use in a pharmacokinetic model. In this study, it was possible to prepare 40 nm sized ICG-liposomes. Small liposomes did not release encapsulated calsein as well as bigger 100 nm liposomes. The decreased release from smaller liposomes was probably explained by the results witch pointed out that transition temperature of small liposomes was higher than transition temperature of bigger liposomes. In the future, the lipid composition of the small liposomes need to be reoptimized, that the release would be more effective. This study however proved that small ICG-liposomes can be prepared and the small size lasts even over three months. Three different formulations of 100 nm liposomes were studied and the differences between the properties of the formulations were found. ICG in the lipid bilayer changed properties of the formulation B and the passive release of the calsein and release during the lightning were increased. In formulation C transition temperature was decreased and its storage life was lower than in other formulations. Formulation A was best for the next studies and the phospholipid composition of other formulations need to be optimated that drug release and storage life would be good enough. Intracellular release properties of liposomes were studied with Sytox red probe. Fluorescence of Sytox red increases when it binds with DNA or RNA. With this study, it was proved that liposomes release Sytox red inside the cells and that the lightning time affects to the release. The results weren't useable for pharmacokinetic model, so the model was made based by literature. Pharmacokinetic model can be used in the future studies and different in vitro or in vivo results can be combined with the model.