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 ◽  
...  

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.

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1210
Author(s):  
Xieguo Yan ◽  
Shiqiang Wang ◽  
Kaoxiang Sun

Schizophrenia, a psychiatric disorder, requires long-term treatment; however, large fluctuations in blood drug concentration increase the risk of adverse reactions. We prepared a long-term risperidone (RIS) implantation system that can stabilize RIS release and established in-vitro and in-vivo evaluation systems. Cumulative release, drug loading, and entrapment efficiency were used as evaluation indicators to evaluate the effects of different pore formers, polymer ratios, porogen concentrations, and oil–water ratios on a RIS implant (RIS-IM). We also built a mathematical model to identify the optimized formulation by stepwise regression. We also assessed the crystalline changes, residual solvents, solubility and stability after sterilization, in-vivo polymer degradation, pharmacokinetics, and tissue inflammation in the case of the optimized formulation. The surface of the optimized RIS microspheres was small and hollow with 134.4 ± 3.5 µm particle size, 1.60 SPAN, 46.7% ± 2.3% implant drug loading, and 93.4% entrapment efficiency. The in-vitro dissolution behavior of RIS-IM had zero-order kinetics and stable blood concentration; no lag time was released for over three months. Furthermore, the RIS-IM was not only non-irritating to tissues but also had good biocompatibility and product stability. Long-acting RIS-IMs with microspheres and film coatings can provide a new avenue for treating schizophrenia.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 635
Author(s):  
Ding Li ◽  
Menglong Wang ◽  
Wen-Liang Song ◽  
Deng-Guang Yu ◽  
Sim Wan Annie Bligh

A side-by-side electrospinning process characterized by a home-made eccentric spinneret was established to produce the Janus beads-on-a-string products. In this study, ketoprofen (KET) and methylene blue (MB) were used as model drugs, which loaded in Janus beads-on-a-string products, in which polyvinylpyrrolidone K90 (PVP K90) and ethyl cellulose (EC) were exploited as the polymer matrices. From SEM images, distinct nanofibers and microparticles in the Janus beads-on-a-string structures could be observed clearly. X-ray diffraction demonstrated that all crystalline drugs loaded in Janus beads-on-a-string products were transferred into the amorphous state. ATR-FTIR revealed that the components of prepared Janus nanostructures were compatibility. In vitro dissolution tests showed that Janus beads-on-a-string products could provide typical double drugs controlled-release profiles, which provided a faster immediate release of MB and a slower sustained release of KET than the electrospun Janus nanofibers. Drug releases from the Janus beads-on-a-string products were controlled through a combination of erosion mechanism (linear MB-PVP sides) and a typical Fickian diffusion mechanism (bead KET-EC sides). This work developed a brand-new approach for the preparation of the Janus beads-on-a-string nanostructures using side-by-side electrospinning, and also provided a fresh idea for double drugs controlled release and the potential combined therapy.


Author(s):  
Rusul M. Alwan ◽  
Nawal A. Rajab

Selexipag is an orally selective long-acting prostacyclin receptor agonist, which indicated for the treatment of pulmonary arterial hypertension. It is practically insoluble in water ( class II, according to BCS). This work aims to prepare and optimized Selexipag nanosuspensions to achieve an enhancement in the in vitro dissolution rate. The solvent antisolvent precipitation method was used for the production of nanosuspension, and the effect of formulation parameters (stabilizer type, drug: stabilizer ratio, and use of co-stabilizer) and process parameter (stirring speed) on the particle size and polydispersity index were studied. SLPNS prepared with Soluplus® as amain stabilizer (F15) showed the smallest particle size 47nm with PDI and Zeta potential value of 0.073 and -47mV, respectively. SLPNS exhibited an increase in the dissolution rate in phosphate buffer pH 6.8 (100% drug release during 60 min) compared to the pure drug ( 40% during the same time). This result indicates that SLPNS is an efficient way of improving the dissolution rate.  


2019 ◽  
Vol 30 (10) ◽  
pp. 2613-2622
Author(s):  
Nagaraja SreeHarsha ◽  
Jagadeesh G. Hiremath ◽  
Rajesh Kumar Aitha ◽  
Abraham J. Domb ◽  
Bandar E. Al‐Dhubiab ◽  
...  

Pharmaceutics ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 213 ◽  
Author(s):  
Evi Christodoulou ◽  
Maria Nerantzaki ◽  
Stavroula Nanaki ◽  
Panagiotis Barmpalexis ◽  
Kleoniki Giannousi ◽  
...  

Magnetic hybrid inorganic/organic nanocarriers are promising alternatives for targeted cancer treatment. The present study evaluates the preparation of manganese ferrite magnetic nanoparticles (MnFe2O4 MNPs) encapsulated within Paclitaxel (PTX) loaded thioether-containing ω-hydroxyacid-co-poly(d,l-lactic acid) (TEHA-co-PDLLA) polymeric nanoparticles, for the combined hyperthermia and chemotherapy treatment of cancer. Initially, TEHA-co-PDLLA semitelechelic block copolymers were synthesized and characterized by 1H-NMR, FTIR, DSC, and XRD. FTIR analysis showed the formation of an ester bond between the two compounds, while DSC and XRD analysis showed that the prepared copolymers were amorphous. MnFe2O4 MNPs of relatively small crystallite size (12 nm) and moderate saturation magnetization (64 emu·g−1) were solvothermally synthesized in the sole presence of octadecylamine (ODA). PTX was amorphously dispersed within the polymeric matrix using emulsification/solvent evaporation method. Scanning electron microscopy along with energy-dispersive X-ray spectroscopy and transmission electron microscopy showed that the MnFe2O4 nanoparticles were effectively encapsulated within the drug-loaded polymeric nanoparticles. Dynamic light scattering measurements showed that the prepared nanoparticles had an average particle size of less than 160 nm with satisfactory yield and encapsulation efficiency. Diphasic PTX in vitro release over 18 days was observed while PTX dissolution rate was mainly controlled by the TEHA content. Finally, hyperthermia measurements and cytotoxicity studies were performed to evaluate the magnetic response, as well as the anticancer activity and the biocompatibility of the prepared nanocarriers.


2018 ◽  
Author(s):  
Shanmuga Sundar Saravanabhavan ◽  
KANNAN NATARAJAN ◽  
Sundaravadivel Elumalai ◽  
Sarang Zsolt ◽  
Mukunthan K SELVAM ◽  
...  

Background The application of polymeric materials in medical industry has grown drastically in the last two decades due to their various advantages compared to existing materials. The present research work emphases on the sol-gel technique to formulate the polymethyl methyl acrylate/polystyrene/silica composite membrane. Methods The characteristic of the composite was investigated through modern state art of instrumentation. Results The functional groups attached to the polymer was absorbed by FTIR. The FTIR spectrum confirm that the blend was mixed thoroughly and the formation of unite intimately between the polymers. The membranes were observed by SEM for its surface homogeneity which depends upon the composition of the two blending polymers. The captured SEM images showed the formation of microcracks on the surface, which was evidently controlled by varying the constituent polymer ratios. The prepared blend membranes with 2:1 ratio of PMMA/PS/Si displayed higher water uptake compared to other blended membranes. The composite membranes had good hydroxyl apatite growth in SBF solution. Furthermore, the in vitro cytotoxicity studies carried out by MTT method, using RAW macrophage cells showed that all the samples exhibited excellent cell viability. Conclusion The inflammatory response of composite with equal concentration of PMMA-PS were performed and observed no inflammation in comparison with control and other tested concentrations.


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