scholarly journals Core-shell poly(lactide-co-ε-caprolactone)-gelatin fiber scaffolds as pH-sensitive drug delivery systems

2018 ◽  
Vol 32 (8) ◽  
pp. 1105-1118 ◽  
Author(s):  
Qingqing Sang ◽  
Heyu Li ◽  
Gareth Williams ◽  
Huanling Wu ◽  
Li-Min Zhu
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Sodium Bicarbonate ◽  
Drug Delivery Systems ◽  
Tumor Resection ◽  
Delivery Systems ◽  
Ph Sensitive ◽  
Core Shell ◽  
Fiber Scaffolds

Dual-drug-loaded pH-responsive fiber scaffolds were successfully prepared by coaxial electrospinning. These were designed with the aim of being sutured into the resection site after tumor removal, to aid recovery and prevent cancer recurrence. The shell was made up of a mixture of gelatin and sodium bicarbonate (added to provide pH-sensitivity), and was loaded with the anti-inflammatory drug ciprofloxacin; the core comprised poly(lactide-co-ε-caprolactone) with the chemotherapeutic doxorubicin hydrochloride. Scanning electron microscopy revealed most fibers were smooth and homogeneous. Transmission electron microscopy demonstrated the presence of a clear core/shell structure. The fiber scaffolds were further characterized using infrared spectroscopy and X-ray diffraction, which proved that both drugs were present in the fibers in the amorphous form. The gelatin shells were cross-linked with glutaraldehyde to enhance their stability, and water contact angle measurements used to confirm they remained hydrophilic after this process, with angles between 10 and 35°. This is important for onward applications, since a hydrophilic surface is known to encourage cell proliferation. During in vitro drug release studies, a rapid and acid-responsive release of ciprofloxacin was seen, accompanied by sustained and long-term doxorubicin release. Both the release profiles and the mechanical strength of the fibers can effectively be tuned through the sodium bicarbonate content of the fibers: for instance, the break stress varies from 2.00 MPa to 2.57 MPa with an increase in sodium bicarbonate content. The pH values of aqueous media exposed to the scaffolds decrease only slightly, by less than 0.5 pH units, over the two-month timescale, suggesting that only minimal fiber degradation occurs during this time. The fiber scaffolds also have good biocompatibility, as revealed by in vitro cytotoxicity experiments. Overall, our results demonstrate that the novel scaffolds reported here are promising pH-sensitive drug delivery systems, and may be candidates for use after tumor resection surgery.

Solid self-emulsifying drug delivery system (Solid SEDDS) for testosterone undecanoate: in vitro and in vivo evaluation

2020 ◽  
Vol 17 ◽  
Author(s):  
Xi Liang ◽  
Yabing Hua ◽  
Qian Liu ◽  
Zhiguo Li ◽  
Fanglin Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Delivery System ◽  
High Fat Diet ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
High Fat ◽  
Testosterone Undecanoate

Objective: The current study aimed to investigate the potential of solid self-emulsifying drug delivery systems (solid SEDDS) loaded with testosterone undecanoate (TU) (solid TU-SEDDS). The solid TU-SEDDS was composed of TU, medium-chain triglycerides (MCT, oil), 2-Chloro-1-(chloromethyl) ethyl carbamate (EL-35, surfactant) and polyethylene glycol (PEG400, cosurfactant). It was expected to improve the dissolution and oral bioavailability of TU, as a result of investigating the feasibility of clinical application of SEDDS. Methods: First, a TU-SEDDS was developed by using rational blends of components with good solubilizing ability for TU. Next, a ternary phase diagram was constructed to determine the self-emulsifying region, and the formulation was optimized. Then, the solid TU-SEDDS formulation was established by screening suitable solid adsorptions. Finally, the prepared SEDDS, TU-SEDDS and solid TU-SEDDS formulations were evaluated in vitro and in vivo. Results: The size of the solid TU-SEDDS was 189.1 ± 0.23 nm. The transmission electron microscopy (TEM) results showed that the oil droplets were homogenous and spherical with good integrity. The differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) results indicated that the solid TU-SEDDS formulation almost preserves the amorphous state. Scanning electron microscopy (SEM) indicated that neusilin US2 successfully adsorbed the TU-SEDDS. Drug release indicated that the dissolution of the solid TU-SEDDS was faster than that of Andriol Testocaps®. Furthermore, in vivo pharmacokinetic (PK) studies in Sprague-Dawley (SD) rats showed that the area under the curve (AUC) of the solid TU-SEDDS (487.54±208.80 µg/L×h) was higher than that of Andriol Testocaps® (418.93±273.52 µg/L×h, P < 0.05). In beagles not fed a high-fat diet, the AUC of the solid TU-SEDDS (5.81±4.03 µg/L×h) was higher than that of Andriol Testocaps® (5.53±3.43 µg/L×h, P > 0.05). In beagles fed a high-fat diet, the AUC of the solid TU-SEDDS (38.18±21.90 µg/L×h) was higher than that of Andriol Testocaps® (37.17±13.79 µg/L×h, P > 0.05). Conclusion: According to the results of this research, oral solid TU-SEDDS is expected to be another alternative delivery system for the late-onset hypogonadism. This is beneficial to the transformation of existing drug delivery systems into preclinical and clinical studies.

scholarly journals Linagliptin loaded Solid-SMEEDS for enhanced solubility and dissolution: Formulation development and optimization by D-optimal design

2019 ◽  
Vol 9 (2) ◽  
pp. 47-56
Author(s):  
Madhubhai M Patel ◽  
Rahulkumar J Patel
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Transmission Electron Microscopy ◽  
Optimal Design ◽  
Zeta Potential ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Dissolution Profile ◽  
Transmission Electron

The aim of the present investigation was to formulate and evaluate solid self-micro emulsifying drug-delivery systems (S-SMEDDS) to improve solubility and dissolution profile of Linagliptin. Solubility of Linagliptin in different oils, surfactants and co-surfactants was assessed and optimizations of pseudo-ternary plots were also carried out for preparation of liquid SMEDDS. D-optimal design mixture was used in the optimization of Linagliptin loaded liquid SMEEDS. The optimized SMEEDS were characterized for globule size, zeta potential, dilution stability, transmittance, pH and in-vitro release profile. The morphology of the Linagliptin SMEEDS was observed by Transmission Electron Microscopy (TEM). Among the different silicates, Nusillin US2 was used as the solid carrier/absorbent to formulate S-SMEEDS of Linagliptin. Improved in-vitro dissolution profile of optimized formulation was observed, resulting in multifold improvement in the absorption profile of Linagliptin as compared with pure drug. In a nutshell, this optimized S-SMEDD formulation holds great promise for enhancement of its physiochemical and biological attributes. Keywords: Linagliptin, Solid Self-micro Emulsifying Drug Delivery Systems, D-optimal design, Zeta-potential, Transmission Electron Microscopy

PEGylated Dendrimer-Doxorubicin Cojugates as pH-Sensitive Drug Delivery Systems: Synthesis and In Vitro Characterization

2015 ◽  
Vol 11 (6) ◽  
pp. 964-978 ◽  
Author(s):  
Wenchuan She ◽  
Dayi Pan ◽  
Kui Luo ◽  
Bin He ◽  
Gang Cheng ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Ph Sensitive

scholarly journals Advanced Static and Dynamic Fluorescence Microscopy Techniques to Investigate Drug Delivery Systems

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 861
Author(s):  
Jacopo Cardellini ◽  
Arianna Balestri ◽  
Costanza Montis ◽  
Debora Berti
Keyword(s):  
Drug Delivery ◽  
Fluorescence Microscopy ◽  
Drug Delivery Systems ◽  
Laser Scanning ◽  
Super Resolution ◽  
Laser Scanning Confocal Microscopy ◽  
Delivery Systems ◽  
Scanning Confocal Microscopy ◽  
Biological Phenomena

In the past decade(s), fluorescence microscopy and laser scanning confocal microscopy (LSCM) have been widely employed to investigate biological and biomimetic systems for pharmaceutical applications, to determine the localization of drugs in tissues or entire organisms or the extent of their cellular uptake (in vitro). However, the diffraction limit of light, which limits the resolution to hundreds of nanometers, has for long time restricted the extent and quality of information and insight achievable through these techniques. The advent of super-resolution microscopic techniques, recognized with the 2014 Nobel prize in Chemistry, revolutionized the field thanks to the possibility to achieve nanometric resolution, i.e., the typical scale length of chemical and biological phenomena. Since then, fluorescence microscopy-related techniques have acquired renewed interest for the scientific community, both from the perspective of instrument/techniques development and from the perspective of the advanced scientific applications. In this contribution we will review the application of these techniques to the field of drug delivery, discussing how the latest advancements of static and dynamic methodologies have tremendously expanded the experimental opportunities for the characterization of drug delivery systems and for the understanding of their behaviour in biologically relevant environments.

scholarly journals Mechanisms and Pharmaceutical Action of Lipid Nanoformulation of Natural Bioactive Compounds as Efficient Delivery Systems in the Therapy of Osteoarthritis

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1108
Author(s):  
Oana Craciunescu ◽  
Madalina Icriverzi ◽  
Paula Ecaterina Florian ◽  
Anca Roseanu ◽  
Mihaela Trif
Keyword(s):  
Drug Delivery ◽  
Bioactive Compounds ◽  
Targeted Delivery ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Joint Disease ◽  
Duration Of Action ◽  
Immune System Activation

Osteoarthritis (OA) is a degenerative joint disease. An objective of the nanomedicine and drug delivery systems field is to design suitable pharmaceutical nanocarriers with controllable properties for drug delivery and site-specific targeting, in order to achieve greater efficacy and minimal toxicity, compared to the conventional drugs. The aim of this review is to present recent data on natural bioactive compounds with anti-inflammatory properties and efficacy in the treatment of OA, their formulation in lipid nanostructured carriers, mainly liposomes, as controlled release systems and the possibility to be intra-articularly (IA) administered. The literature regarding glycosaminoglycans, proteins, polyphenols and their ability to modify the cell response and mechanisms of action in different models of inflammation are reviewed. The advantages and limits of using lipid nanoformulations as drug delivery systems in OA treatment and the suitable route of administration are also discussed. Liposomes containing glycosaminoglycans presented good biocompatibility, lack of immune system activation, targeted delivery of bioactive compounds to the site of action, protection and efficiency of the encapsulated material, and prolonged duration of action, being highly recommended as controlled delivery systems in OA therapy through IA administration. Lipid nanoformulations of polyphenols were tested both in vivo and in vitro models that mimic OA conditions after IA or other routes of administration, recommending their clinical application.

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