scholarly journals An injectable in situ lipid phase transition system for sustained delivery of dabigatran etexilate with low burst release

RSC Advances ◽  
2017 ◽  
Vol 7 (89) ◽  
pp. 56594-56601
Author(s):  
Xuanmiao Zhang ◽  
Mei Hu ◽  
Guangfei Wei ◽  
Mengdi Jia ◽  
Tao Gong ◽  
...  
Keyword(s):  
Phase Transition ◽  
Sustained Release ◽  
Dabigatran Etexilate ◽  
Transition System ◽  
Lipid Phase ◽  
Burst Release ◽  
Sustained Delivery ◽  
Lipid Phase Transition ◽  
Initial Burst

The first report of dabigatran exilate sustained release injection that exhibited great potential in controlling initial burst release.

scholarly journals Parenteral Sustained Release Lipid Phase-Transition System of Ziprasidone: Fabrication and Evaluation for Schizophrenia Therapy

2020 ◽  
Vol Volume 14 ◽  
pp. 2237-2247
Author(s):  
Urooj Ahmed Khan ◽  
Uzma Parveen ◽  
Nazeer Hasan ◽  
Mohammad Zubair Ahmed ◽  
Suma Saad ◽  
...  
Keyword(s):  
Phase Transition ◽  
Sustained Release ◽  
Transition System ◽  
Lipid Phase ◽  
Lipid Phase Transition

The impacts of PLGA/PEG triblock copolymers with variable molecular weights on sustained release of buprenorphine

2021 ◽  
Vol 18 ◽  
Author(s):  
Hossein Kamali ◽  
Elham Khodaverdi ◽  
Fatemeh Mohammadpour ◽  
Ali Kakavand ◽  
Seyedeh Nesa Rezaeian Shiadeh ◽  
...  
Keyword(s):  
Sustained Release ◽  
Sol Gel ◽  
In Vitro Release ◽  
Burst Release ◽  
Sustained Release Formulation ◽  
Melting Method ◽  
Initial Burst ◽  
Initial Burst Release ◽  
Molecular Weights

Introduction: Current in-situ injectable implants of buprenorphine (BP) such as Sublocade® consist of N-methyl-2-pyrrolidone (NMP)-dissolved PLGA. To control the initial burst release of Sublocade® during the first 24 hours after injection, we used a BP in-situ forming composite (ISFC) to employ different molecular weights of PLGA-PEG-PLGA triblock. Methods: The triblock was synthesized by ring-opening polymerization (ROP) using PEG molecules with weights of 1500, 3000, and 4000 Da via the melting method. The specifications of the triblock were evaluated by 1H-NMR, FTIR, GPC, and DSC. The sol-gel, gel-precipitate temperatures, in-vitro release, and composites’ morphology, degradation, and toxicity were assessed for determining the features of ISFC 1500, ISFC 3000, and ISFC 4000 formulations. ROP was performed successfully via the melting method. The yields of all polymerization reactions were greater than 83.4 %. Results: The PEG 1500 triblock showed both sol-gel and gel-precipitate temperatures, but PEG 3000 and 4000 only showed a sol-precipitate temperature. The values of initial burst release of BP from ISFC 1500, ISFC 3000, and ISFC 4000 were 6.52 ± 0.22 %, 12.39 ± 0.61 %, and 15.80 ± 0.98 %, respectively. BP release from the ISFCs was completed over three weeks for ISFC 1500 and 10 days for ISFC 3000 and ISFC 4000. The composites containing PEG 3000 and PEG 4000 were more spongy and porous than PEG 1500. The ISFC 1500 delivered a higher cell viability (95.17 ± 1.15 %) compared with ISFC 3000 (86.37 ± 2.25%) and ISFC 4000 (79.70 ± 3.77%). Conclusion: These results indicated that ISFC 1500 were biocompatible and delivered suitable early initial burst reactions compared with ISFC 3000 and 4000 and might be a good candidate for preparing sustained-release formulation of BP.

Fatty acyl chain structure, orientational order, and the lipid phase transition in Acholeplasma laidlawii B membranes. A review of recent 19F nuclear magnetic resonance studies

1984 ◽  
Vol 62 (11) ◽  
pp. 1134-1150 ◽  
Author(s):  
P. M. Macdonald ◽  
B. D. Sykes ◽  
R. N. McElhaney
Keyword(s):  
Phase Transition ◽  
Fatty Acids ◽  
Nuclear Magnetic Resonance ◽  
Acyl Chain ◽  
Orientational Order ◽  
Membrane Lipid ◽  
Fatty Acyl ◽  
Fatty Acyl Chain ◽  
Lipid Phase ◽  
Lipid Phase Transition

The orientational order parameters of monofluoropalmitic acids biosynthetically incorporated into membranes of Acholeplasma laidlawii B in the presence of a large excess of a variety of structurally diverse fatty acids have been determined via 19F nuclear magnetic resonance (19F NMR) spectroscopy. It is demonstrated that these monofluoropalmitic acids are relatively nonperturbing membrane probes based upon physical (differential scanning calorimetry), biochemical (membrane lipid analysis), and biological (growth studies) criteria. 19F NMR is shown to convey the same qualitative and quantitative picture of membrane lipid order provided by 2H-NMR techniques and to be sensitive to the structural characteristics of the membrane fatty acyl chains, as well as to the lipid phase transition. Representatives of each naturally occurring class of fatty acyl chain structures, including straight-chain saturated, methyl-branched, monounsaturated, and alicyclic-ring-substituted fatty acids, were studied and the 19F-NMR order parameters were correlated with the lipid phase transitions (determined calorimetrically). The lipid phase transition was the prime determinant of overall orientational order regardless of fatty acid structure. Effects upon orientational order attributable to specific structural substituents were discernible, but were secondary to the effects of the lipid phase transition. In the gel state, relative overall order was directly proportional to the temperature of the particular lipid phase transition. Not only the overall order, but also the order profile across the membrane was sensitive to the presence of particular structural substituents. In particular, in the gel state specific fatty acyl structures demonstrated a characteristic disordering effect in the membrane order profile. These various observations can be merged to provide a unified picture of the manner in which fatty acyl chain chemistry modulates the physical state of membrane lipids.

The incorporation of cholesterol into inner mitochondrial membranes and its effect on lipid phase transition

1980 ◽  
Vol 599 (2) ◽  
pp. 528-537 ◽  
Author(s):  
Thomas D. Madden ◽  
Carmen Vigo ◽  
K.Richard Bruckdorfer ◽  
Dennis Chapman
Keyword(s):  
Phase Transition ◽  
Lipid Phase ◽  
Mitochondrial Membranes ◽  
Lipid Phase Transition

Injectable in situ gelling delivery system for the treatment of jawbone infections

2021 ◽  
Author(s):  
Shreshtha Dash ◽  
Somnath Singh ◽  
Alekha K Dash
Keyword(s):  
Lactic Acid ◽  
Sustained Release ◽  
Cell Viability ◽  
Yield Stress ◽  
Delivery System ◽  
Pluronic F127 ◽  
Sustained Delivery ◽  
In Situ Gelling ◽  
Sustained Rate

Aim: A polymeric in situ gelling delivery system for localized and sustained delivery to jawbone infections was developed. Materials & methods: In situ gelling delivery systems were prepared using either poly-dl-lactic acid or chitosan and Pluronic F127/Pluronic F68. Metronidazole nanoparticles were prepared using poly (dl-lactide-co-glycolide) or chitosan. Poly (dl-lactide-co-glycolide) was used for microparticles. Particles were characterized for size, charge and morphology. Results: Viscosity and yield stress of the gels were 0.4 Pa.s and 2 Pa, respectively, with 70% cell viability over 72 h. Around 90% of loaded metronidazole was released at a sustained rate over 1 week. Conclusion: Use of appropriate amount of nano/microparticles in the gel resulted in a sustained release over a period of 1 week – needed for jawbone infection.

Some Aspects of Lipid-Phase Transition on Membrane Permeability and Lipid-Protein Association

1977 ◽  
pp. 38-46 ◽  
Author(s):  
M. C. Blok ◽  
L. L. M. van Deenen ◽  
J. de Gier ◽  
J. A. F. Op den Kamp ◽  
A. J. Verkleij
Keyword(s):  
Phase Transition ◽  
Membrane Permeability ◽  
Lipid Phase ◽  
Lipid Phase Transition ◽  
Protein Association

Sucrose Acetate Isobutyrate as an In situ Forming Implant for Sustained Release of Local Anesthetics

2019 ◽  
Vol 16 (4) ◽  
pp. 331-340
Author(s):  
Hanmei Li ◽  
Yuling Xu ◽  
Yuna Tong ◽  
Yin Dan ◽  
Tingting Zhou ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Sustained Release ◽  
Local Anesthetics ◽  
Subcutaneous Injection ◽  
In Vitro Release ◽  
Pharmacokinetic Analysis ◽  
Burst Release

Objective: In this study, an injectable Sucrose Acetate Isobutyrate (SAIB) drug delivery system (SADS) was designed and fabricated for the sustained release of Ropivacaine (RP) to prolong the duration of local anesthesia. Methods: By mixing SAIB, RP, and N-methyl-2-pyrrolidone, the SADS was prepared in a sol state with low viscosity before injection. After subcutaneous injection, the pre-gel solution underwent gelation in situ to form a drug-released depot. Result: The in vitro release profiles and in vivo pharmacokinetic analysis indicated that RP-SADS had suitable controlled release properties. Particularly, the RP-SADS significantly reduced the initial burst release after subcutaneous injection in rats. Conclusion: In a pharmacodynamic analysis of rats, the duration of nerve blockade was prolonged by over 3-fold for the RP-SADS formulation compared to RP solution. Additionally, RP-SADS showed good biocompatibility in vitro and in vivo. Thus, the SADS-based depot technology is a safe drug delivery strategy for the sustained release of local anesthetics with long-term analgesia effects.

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