scholarly journals New Biodegradable Poly(l-lactide)-Block-Poly(propylene adipate) Copolymer Microparticles for Long-Acting Injectables of Naltrexone Drug

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 852 ◽  
Author(s):  
Stavroula Nanaki ◽  
Athina Viziridou ◽  
Alexandra Zamboulis ◽  
Margaritis Kostoglou ◽  
Georgios Z. Papageorgiou ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Drug Release ◽  
Amorphous State ◽  
Copolymer Composition ◽  
Polymeric Matrices ◽  
Release Studies ◽  
Biodegradable Poly ◽  
Long Acting ◽  
Poly Propylene ◽  
Tga And Dsc

In the present study, novel block copolymers of poly(l-lactide)-block-poly(propylene adipate) (PLLA-b-PPAd) were synthesized in two ratios, 90/10 and 75/25 w/w and were further investigated as long-acting injectable (LAI) polymeric matrices in naltrexone base microparticle formulations. The synthesized polymers were characterized by 1H-NMR, 13C-NMR, FTIR, XRD, TGA and DSC. NMR and FTIR spectroscopies confirmed the successful synthesis of copolymers while DSC showed that these are block copolymers with well-defined and separated blocks. Microparticles were prepared by single emulsification method and were further characterized. Nanoparticles in the range of 0.4–4.5 μm were prepared as indicated by SEM, with copolymers giving the lowest particle size. By XRD and DSC it was found that naltrexone was present in the amorphous state in its microparticles. Dissolution study showed a drug release extending over seven days, indicating that these novel PLLA-b-PPAd copolymers could be promising matrices for naltrexone’s LAI formulations. It was evidenced that drug release depended on the copolymer composition. Model release studies showed that drug release is controlled by diffusion.

scholarly journals Synthesis, Degradation, Biocompatibility and Drug Release Studies of Bis 2-Hydroxy Ethyl Terephthalate-based Poly(Mannitol-Citric-Sebacate) Ester

2016 ◽  
Vol 1 (1) ◽  
pp. 9-16
Author(s):  
Athira K Sunil ◽  
Sarkar K ◽  
Kaushik Chatterjee
Keyword(s):  
Drug Release ◽  
Drug Carrier ◽  
Condensation Process ◽  
Burst Release ◽  
Release Studies ◽  
Biodegradable Poly ◽  
Model Drug ◽  
Melt Condensation

Bis 2-Hydroxy Ethyl Terephthalate-based biodegradable poly(mannitol-citric-sebacate) has been synthesized by catalyst-free melt condensation process using two different diacids and Bis 2-Hydroxy Ethyl Terephthalate with D-mannitol as monomers having a potential to be metabolized in vivo. The biocompatibility of the polymer, Bis 2-Hydroxy Ethyl Terephthalate-poly(mannitol-citric-sebacate) has been tested using human primary stromal cells. In vitro degradation of Bis 2-Hydroxy Ethyl Terephthalate-poly(mannitol-citric-sebacate) polymer in Phosphate Buffered Saline solution carried out at physiological conditions indicates that the degradation goes to completion after 23 days. The usage of Bis 2-Hydroxy Ethyl Terephthalate-poly(mannitol-citric-sebacate) polymer as a drug carrier has been analyzed by doping the polymer with Doxorubicin model drug and the release rate has been studied by mass loss over time. The cumulative drug-release profiles exhibit a biphasic release with an initial burst release and cumulative 100 percent release within 14 days.

scholarly journals Amphiphilic electrospun scaffolds of PLLA–PEO–PPO block copolymers: preparation, characterization and drug-release behaviour

RSC Advances ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 161-172 ◽  
Author(s):  
Lívia M. D. Loiola ◽  
Pablo R. Cortez Tornello ◽  
Gustavo A. Abraham ◽  
Maria I. Felisberti
Keyword(s):  
Block Copolymers ◽  
Drug Release ◽  
Encapsulation Efficiency ◽  
Copolymer Composition ◽  
Hydrophobic Drugs ◽  
Electrospun Scaffolds ◽  
Nanofibrous Scaffolds

Drug-loaded nanofibrous scaffolds containing hydrophilic or hydrophobic drugs presented encapsulation efficiency, distribution and release dependent on copolymer composition.

scholarly journals Risperidone Controlled Release Microspheres Based on Poly(Lactic Acid)-Poly(Propylene Adipate) Novel Polymer Blends Appropriate for Long Acting Injectable Formulations

Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 130 ◽  
Author(s):  
Stavroula Nanaki ◽  
Panagiotis Barmpalexis ◽  
Alexandros Iatrou ◽  
Evi Christodoulou ◽  
Margaritis Kostoglou ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Controlled Release ◽  
Drug Release ◽  
Polymer Blends ◽  
Solvent Evaporation ◽  
Poly Lactic Acid ◽  
Solvent Evaporation Method ◽  
Evaporation Method ◽  
Long Acting ◽  
Poly Propylene

The present study evaluates the preparation of risperidone controlled release microspheres as appropriate long-acting injectable formulations based on a series of novel biodegradable and biocompatible poly(lactic acid)–poly(propylene adipate) (PLA/PPAd) polymer blends. Initially, PPAd was synthesized using a two-stage melt polycondensation method (esterification and polycondensation) and characterized by 1H-NMR, differential scanning calorimetry (DSC), and powder X-ray diffraction (XRD) analyses. DSC and XRD results for PLA/PPAd blends (prepared by the solvent evaporation method) showed that these are immiscible, while enzymatic hydrolysis studies performed at 37 °C showed increased mass loss for PPAd compared to PLA. Risperidone-polyester microparticles prepared by the oil–water emulsification/solvent evaporation method showed smooth spherical surface with particle sizes from 1 to 15 μm. DSC, XRD, and Fourier-transformed infrared (FTIR) analyses showed that the active pharmaceutical ingredient (API) was dispersed in the amorphous phase within the polymer matrices, whereas in vitro drug release studies showed risperidone controlled release rates in all PLA/PPAd blend formulations. Finally, statistical moment analysis showed that polyester hydrolysis had a major impact on API release kinetics, while in PLA/PPAd blends with high PLA content, drug release was mainly controlled by diffusion.

scholarly journals Chemoenzymatic Synthesis of Dual-responsive Amphiphilic Block Copolymers and Drug Release Studies

2013 ◽  
Vol 34 (6) ◽  
pp. 1800-1808
Author(s):  
Peng Chen ◽  
Ya-Peng Li ◽  
Shu-Wei Wang ◽  
Xin-Lei Meng ◽  
Ming Zhu ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Drug Release ◽  
Amphiphilic Block Copolymers ◽  
Chemoenzymatic Synthesis ◽  
Dual Responsive ◽  
Release Studies

Synthesis, Characterization and in-vitro drug release studies of a macromolecular prodrug of Didanosine.

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Neeraj Agrawal ◽  
M.J. Chandrasekar ◽  
U.V. Sara ◽  
Rohini A.
Keyword(s):  
Drug Release ◽  
Drug Level ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
In Vitro Drug Release ◽  
Alkaline Environment ◽  
Stomach Acid ◽  
Release Studies ◽  
Macromolecular Prodrug

A macromolecular prodrug of didanosine (ddI) for oral administration was synthesized and evaluated for in-vitro drug release profile. Didanosine was first coupled to 2-hydroxy ethyl methacrylate (HEMA) through a succinic spacer to form HEMA-Suc-ddI monomeric conjugate which was subsequently polymerized to yield Poly(HEMA-Suc-ddI) conjugate. The structures of the synthesized compounds were characterized by FT-IR, Mass and 1H-NMR spectroscopy. The prodrug was subjected for in-vitro drug release studies in buffers of pH 1.2 and 7.4 mimicking the upper and lower GIT. The results showed that the drug release from the polymeric backbone takes place in a sustained manner over a period of 24 h and the amount of drug released was comparatively higher at pH 7.4 indicating that the drug release takes place predominantly at the alkaline environment of the lower GIT rather than at the acidic environment of the upper GIT. This pH dependent sustained drug release behavior of the prodrug may be capable of reducing the dose limiting toxicities by maintaining the plasma drug level within the therapeutic range and increasing t1/2 of ddI. Moreover, the bioavailability of the drug should be improved as the prodrug releases ddI predominantly in the alkaline environment which will reduce the degradation of ddI in the stomach acid.

Design and Evaluation of Long Acting Biodegradable PLGA Microspheres for Ocular Drug Delivery

2019 ◽  
Vol 10 ◽  
Author(s):  
Anjali Pandya ◽  
Rajani Athawale ◽  
Durga Puro ◽  
Geeta Bhagwat
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Degradation Products ◽  
Ex Vivo ◽  
Research Work ◽  
Entrapment Efficiency ◽  
Rational Approach ◽  
Plga Microspheres ◽  
Long Acting

Background: The research work involves development of PLGA biodegradable microspheres loaded with dexamethasome for intraocular delivery. Objective: To design and evaluate long acting PLGA microspheres for ocular delivery of dexamethasone. Method: Present formulation involves the development of long acting dexamethasone loaded microspheres composed of a biodegradable controlled release polymer, Poly(D, L- lactide-co-glycolide) (PLGA), for the treatment of posterior segment eye disorders intravitreally. PLGA with monomer ratio of 50:50 of lactic acid to glycolic acid was used to achieve a drug release up to 45 days. Quality by Design approach was utilized for designing the experiments. Single emulsion solvent evaporation technique along with high pressure homogenization was used to facilitate formation of microspheres. Results: Particle size evaluation, drug content and drug entrapment efficiency were determined for the microspheres. Particle size and morphology was observed using Field Emission Gun-Scanning Electron Microscopy (FEG-SEM) and microspheres were in the size range of 1-5 μm. Assessment of drug release was done using in vitro studies and transretinal permeation was observed by ex vivo studies using goat retinal tissues. Conclusion: Considering the dire need for prolonged therapeutic effect in diseases of the posterior eye, an intravitreal long acting formulation was designed. Use of biodegradable polymer with biocompatible degradation products was a rational approach to achieve this aim. Outcome from present research shows that developed microspheres would provide a long acting drug profile and reduce the frequency of administration thereby improving patient compliance.

Synthesis and characterization of Chitosan-Catechol conjugates: Development and in vitro, in silico and in vivo evaluation of mucoadhesive pellets of lafutidine

2021 ◽  
pp. 088391152199784
Author(s):  
Loveleen Kaur ◽  
Ajay Kumar Thakur ◽  
Pradeep Kumar ◽  
Inderbir Singh
Keyword(s):  
Drug Release ◽  
In Silico ◽  
Ex Vivo ◽  
Strong Interactions ◽  
Dissolution Time ◽  
Sem Images ◽  
In Vivo Evaluation ◽  
Release Studies

Present study was aimed to synthesize and characterize Chitosan-Catechol conjugates and to design and develop mucoadhesive pellets loaded with lafutidine. SEM images indicated the presence of fibrous structures responsible for enhanced mucoadhesive potential of Chitosan-Catechol conjugates. Thermodynamic stability and amorphous nature of conjugates was confirmed by DSC and XRD studies respectively. Rheological studies were used to evaluate polymer mucin interactions wherein strong interactions between Chitosan-Catechol conjugate and mucin was observed in comparison to pristine chitosan and mucin. The mucoadhesion potential of Chitosan-Catechol (Cht-C) versus Chitosan (Cht) was assessed in silico using molecular mechanics simulations and the results obtained were compared with the in vitro and ex vivo results. Cht-C/mucin demonstrated much higher energy stabilization (∆E ≈ −65 kcal/mol) as compared to Cht/mucin molecular complex. Lafutidine-loaded pellets were prepared from Chitosan (LPC) and Chitosan-Catechol conjugates (LPCC) and were evaluated for various physical properties viz. flow, circularity, roundness, friability, drug content, particle size and percent mucoadhesion. In vitro drug release studies on LPC and LPCC pellets were performed for computing t50%, t90% and mean dissolution time. The values of release exponent from Korsmeyer-Peppas model was reported to be 0.443 and 0.759 for LPC and LPCC pellets suggesting Fickian and non-Fickian mechanism representing drug release, respectively. In vivo results depicted significant controlled release and enhanced residence of the drug after being released from the chitosan-catechol coated pellets. Chitosan-Catechol conjugates were found to be a promising biooadhesive polymer for the development of various mucoadhesive formulations.

scholarly journals Novel Hydrogels of Chitosan and Poly (vinyl alcohol) Reinforced with Inorganic Particles of Bioactive Glass

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 691
Author(s):  
O. Sánchez-Aguinagalde ◽  
Ainhoa Lejardi ◽  
Emilio Meaurio ◽  
Rebeca Hernández ◽  
Carmen Mijangos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Drug Release ◽  
Bioactive Glass ◽  
Vinyl Alcohol ◽  
Release Kinetics ◽  
The Body ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Inorganic Particles ◽  
Release Studies

Chitosan (CS) and poly (vinyl alcohol) (PVA) hydrogels, a polymeric system that shows a broad potential in biomedical applications, were developed. Despite the advantages they present, their mechanical properties are insufficient to support the loads that appear on the body. Thus, it was proposed to reinforce these gels with inorganic glass particles (BG) in order to improve mechanical properties and bioactivity and to see how this reinforcement affects levofloxacin drug release kinetics. Scanning electron microscopy (SEM), X-ray diffraction (XRD), swelling tests, rheology and drug release studies characterized the resulting hydrogels. The experimental results verified the bioactivity of these gels, showed an improvement of the mechanical properties and proved that the added bioactive glass does affect the release kinetics.

scholarly journals Poly(l-Lactic Acid)-co-poly(Butylene Adipate) New Block Copolymers for the Preparation of Drug-Loaded Long Acting Injectable Microparticles

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 930
Author(s):  
Vasiliki Karava ◽  
Aggeliki Siamidi ◽  
Marilena Vlachou ◽  
Evi Christodoulou ◽  
Nikolaos D. Bikiaris ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Block Copolymers ◽  
In Vitro Dissolution ◽  
Sem Images ◽  
Exterior Surface ◽  
Erosion Rates ◽  
Cytotoxicity Studies ◽  
Release Data ◽  
Long Acting

The present study evaluates the use of newly synthesized poly(l-lactic acid)-co-poly(butylene adipate) (PLA/PBAd) block copolymers as microcarriers for the preparation of aripiprazole (ARI)-loaded long acting injectable (LAI) formulations. The effect of various PLA to PBAd ratios (95/5, 90/10, 75/25 and 50/50 w/w) on the enzymatic hydrolysis of the copolymers showed increasing erosion rates by increasing the PBAd content, while cytotoxicity studies revealed non-toxicity for all prepared biomaterials. SEM images showed the formation of well-shaped, spherical MPs with a smooth exterior surface and no particle’s agglomeration, while DSC and pXRD data revealed that the presence of PBAd in the copolymers favors the amorphization of ARI. FTIR spectroscopy showed the formation of new ester bonds between the PLA and PBAd parts, while analysis of the MP formulations showed no molecular drug–polyester matrix interactions. In vitro dissolution studies suggested a highly tunable biphasic extended release, for up to 30 days, indicating the potential of the synthesized copolymers to act as promising LAI formulations, which will maintain a continuous therapeutic level for an extended time period. Lastly, several empirical and mechanistic models were also tested, with respect to their ability to fit the experimental release data.

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