scholarly journals Release of a Wound-Healing Agent from PLGA Microspheres in a Thermosensitive Gel

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
H. A. Machado ◽  
J. J. Abercrombie ◽  
T. You ◽  
P. P. DeLuca ◽  
K. P. Leung

The purpose of this research was to develop a topical microsphere delivery system in a thermosensitive 20% poloxamer 407 gel (Pluronic F127) to control release of KSL-W, a cationic antimicrobial decapeptide, for a period of 4–7 days for potential application in combat related injuries. KSL-W loaded microsphere formulations were prepared by a solvent extraction-evaporation method (water-oil-water), with poly (D,L-lactic-co-glycolic acid) (PLGA) (50 : 50, low-weight, and hydrophilic end) as the polymeric system. After optimization of the process, three formulations (A, B, and C) were prepared with different organic to water ratio of the primary emulsion while maintaining other components and manufacturing parameters constant. Formulations were characterized for surface morphology, porous nature, drug loading,in vitrodrug release, and antimicrobial activity. Microspheres containing 20% peptide with porous surfaces and internal structure were prepared in satisfactory yields and in sizes varying from 25 to 50 μm. Gels of 20% Pluronic F127, which were liquid at or below 24.6°C and formed transparent films at body temperature, were used as carriers for the microspheres. Rheological studies showed a gelation temperature of 24.6°C for the 20% Pluronic F127 gel alone. Gelation temperature and viscosity of formulations A, B, and C as a function of temperature were very close to those of the carrier. A Franz diffusion cell system was used to study the release of peptide from the microspheres suspended in both, phosphate-buffered saline (PBS) and a 20% Pluronic F127 gel.In vitrorelease of greater than 50% peptide was found in all formulations in both PBS and the gel, and in one formulation there was a release of 75% in both PBS and the gel. Fractions collected from the release process were also tested for bactericidal activity againstStaphylococcus epidermidisusing the broth microdilution method and found to provide effective antimicrobial activity to warrant consideration and testing in animal wound models for treating combat-related injuries.

2018 ◽  
Vol 7 (3) ◽  
pp. 122-129
Author(s):  
Fatma Youcefi ◽  
Ali Riazi ◽  
Meriem Mokhtar ◽  
Tefiani Choukri ◽  
Khaouani Naima

Chitosan is the most abundant natural organic polymer in nature. Its positive charge and its molecular arrangement confer interesting properties on the plane food, pharmaceutical, medical, cosmetic, water treatment. The present study was undertaken to study the physiochemical parameters and the in vitro antimicrobial activity of chitosan extracted from shrimp shells waste. The molecular weight of chitosan is 1414.33±16.99 kDa with, the percent of Ash 0,345±0,040 %, moisture is 2,98 ±0,13 % , and protein is 0.3 ±0,041 %.Chitosan produced (5 %) was also characterized with Fourier Transform Infrared Spectroscopy (FTIR) the spectrum of the chitosan sample from the shell recorded 16 peaks in the range of 689.40/cm and 3430.02 /cm. The antibacterial and antifungul activities of chitosan were examined against Escherichia coli ATCC10536, Pseudomonas aeruginosa ATCC 27853, Listeria monocytogenes ATCC7644, Staphylococcus aureus ATCC29213, Aspergillus niger ATCC 16888 and Candida albicans ATCC 10231 by agar wells diffusion the tests inhibitions zones diameters were 49,74± 0,75 , 54,35±0,93 , 42,27±1,07 , 32,95±0,28 and 53,73±0,64mm respectively. The minimum inhibitory concentration (MIC) using a broth microdilution method against tested microorganisms was ranging from 008% to 1.22%. These results open interesting perspectives of the chitosan. It can be used as new biomaterial with utility in many industrial areas.


Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1309
Author(s):  
Davide Carcione ◽  
Claudia Siracusa ◽  
Adela Sulejmani ◽  
Roberta Migliavacca ◽  
Alessandra Mercato ◽  
...  

Background: Cefiderocol is a siderophore cephalosporin that exhibits antimicrobial activity against most multi-drug resistant Gram-negative bacteria, including Enterobacterales, Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia. Methods: A total of 20 multidrug-resistant A. baumannii strains were isolated from 2020 to 2021, molecularly characterized and tested to assess the in vitro antibacterial activity of cefiderocol. Thirteen strains were carbapenem-hydrolysing oxacillinase OXA-23-like producers, while seven were non-OXA-23-like producers. Minimum inhibitory concentrations (MICs) were determined by broth microdilution, considered as the gold standard method. Disk diffusion test was also carried out using iron-depleted CAMHB plates for cefiderocol. Results: Cefiderocol MICs ranged from 0.5 to 1 mg/L for OXA-23-like non-producing A. baumannii strains and from 0.25 to >32 mg/L for OXA-23-like producers, using the broth microdilution method. Cefiderocol MIC90 was 8 mg/L. Diameter of inhibition zone of cefiderocol ranged from 18 to 25 mm for OXA-23-like non-producers and from 15 to 36 mm for OXA-23-like producers, using the diffusion disk method. A large variability and a low reproducibility were observed during the determination of diameter inhibition zone. Molecular characterization showed that all isolates presented the ISAba1 genetic element upstream the blaOXA-51. Among OXA-23-like non-producers, four were blaOXA-58 positive and two were negative for all the resistance determinants analyzed. Conclusions: Cefiderocol showed in vitro antimicrobial activity against both carbapenem-susceptible and non-susceptible A. baumannii strains, although some OXA-23-like producers were resistant. Further clinical studies are needed to consolidate the role of cefiderocol as an antibiotic against MDR A. baumannii.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Zhaohui Li ◽  
Congqin Ning ◽  
Dongyan Ding ◽  
Hegang Liu ◽  
Lin Huang

Surface modification of low modulus implant alloys with oxide nanostructures is one of the important ways to achieve favorable biological behaviors. In the present work, amorphous Ti-Nb-Zr-O nanostructures were grown on a peak-aged Ti35Nb5Zr alloy through anodization. Biological properties of the Ti-Nb-Zr-O nanostructures were investigated throughin vitrobioactivity testings, stem cell interactions, and drug release experiments. The Ti-Nb-Zr-O nanostructures demonstrated a good capability of inducing apatite formation after immersion in simulated body fluids (SBFs). Drug delivery experiment based on gentamicin and the Ti-Nb-Zr-O nanostructures indicated that a high drug loading content could result in a prolonged release process and a higher quantity of drug residues in the oxide nanostructures after drug release. Quick stem cell adhesion and spreading, as well as fast formation of extracellular matrix materials on the surfaces of the Ti-Nb-Zr-O nanostructures, were found. These findings make it possible to further explore the biomedical applications of the Ti-Nb-Zr-O nanostructure modified alloys especially clinical operation of orthopaedics by utilizing the nanostructures-based drug-release system.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3376
Author(s):  
Kamran Hidayat Ullah ◽  
Faisal Raza ◽  
Syed Mohsin Munawar ◽  
Muhammad Sohail ◽  
Hajra Zafar ◽  
...  

The current study aimed to develop poloxamer 407 (P407) gel for transungual delivery of antifungal hydrophobic drugs with sufficient gel strength and drug loading. Gel strength and drug loading of P407 gel was improved by use of functional additives. Hydration enhancement effect was used to select optimum nail penetration enhancer. Face-centered central composite design (FCCCD) was used to observe the effect of the selected penetration enhancer (thioglycolic acid (TGA)) and cosolvent (ethanol) on gelation behavior to develop formulation with enough loading of hydrophobic drug, i.e., terbinafine HCl (TBN), and its permeation across the nail plate without compromising on gel strength. It was observed that increasing concentration of P407 and TGA significantly reduced gelation temperature and enhanced the gel strength of P407 gel and can be used to improve P407 gel strength. Under the scanning electron microscope, the significant effect of TGA as an ungual penetration enhancer was observed on the morphology of the nail plate. Optimized P407 gel prepared with modified cold method showed a gelation temperature of 8.7 ± 0.16 °C, gel strength of 122 ± 7.5 s and drug loading of 1.2% w/w, which was four times more than the drug loading in the gels prepared with conventional cold method. Rheological behavior was pseudoplastic with 47.75 ± 3.48% of gel erosion after 12 washings and 67.21 ± 2.16% of drug release after 12 h. A cumulative amount of TBN permeated from P407 gel with and without PE after 24 h was 27.30 ± 4.18 and 16.69 ± 2.31 µg/cm2, respectively. Thioglycolic acid can be used as a nail penetration enhancer without the chemical modification or addition of extra additives while retaining the gel strength. Water miscible cosolvents with moderate evaporability such as ethanol, can be incorporated to P407 gel by minor modification in method of preparation to load the required dose of hydrophobic drugs. Developed P407 gel formulation with sufficient gel strength and drug loading will be a promising carrier for transungual delivery of hydrophobic antifungal agents.


2020 ◽  
Vol 10 (3-s) ◽  
pp. 169-175
Author(s):  
Ankita Srivastava ◽  
Sharav Desai ◽  
Hitesh Jain ◽  
D.B. Meshram

Emulgel have emerged as one of the most interesting topical delivery system as it has dual control release system i.e gel and emulsion. Topical applications of drug offers many advantages for delivering drug directly to the site of action and deliver the drug for extended period of time at effected site. The major objective behind this formulation is to enhance topical delivery of hydrophobic drug (Fusidic acid) by formulating Fusidic acid emulgel by using carbopol 934 as gelling agent. In addition light liquid paraffin as oil, span 20 as emulsifier and propylene glycol as co-surfactant were selected for the preparation of emulgel. Fusidic acid is steroidal bacteriostatic agent produced from Fusidium coccineum fungus belongs to class of steroids but has no corticosteroids effect and which is useful for the treatment of number of infections. Fusidic acid binds to protein and ribosomes and inhibits bacterial protein synthesis. The prepared emulgel were evaluated for their physical appearance, pH determination, viscosity, spreadability, in-vitro drug release, antimicrobial activity, skin irritation study and stability. All the prepared emulgel showed acceptable physical properties. The best formulation E9 shows better drug release when compared to all formulation. Keywords: Emulgel, Carbopol 934, Topical formulation, Antimicrobial activity, optimization, Fusidic acid


2020 ◽  
Vol 17 ◽  
Author(s):  
Manoj Kumar Mishra ◽  
Jitendra Gupta ◽  
Reena Gupta

Background: Methotrexate (MTX) is a water-insoluble, anti-tumor agent, causes adverse effects like bone marrow suppression, chronic interstitial obstructive pulmonary disease, hepatotoxicity, leukopenia, interstitial pneumonitis and nephrotoxicity with slow drug release rate. Objective: The present study was aimed for successfully incorporating of MTX into novel-targeted Pluronic (PEO-PPOPEO tri-block co-polymer) F127 polymeric micelles intended for intravenous administration with improved drug loading and sustained release behavior necessary to achieve better efficacy of MTX. Method: MTX-loaded Pluronic F127 micelles were characterized for critical micelle concentration, particle size and zeta potential, 1H NMR, drug loading, encapsulation efficiency characterization, cell uptake, in-vitro release study along with partition coefficient and solubilization thermodynamics. Results: The micellar formulation resulted in nano size 27.32±1.43nm of PF127/SDS, as compared to Pluronic F127 micelles or PF127/Phosphatidyl choline which were 30.52±1.18nm and 154.35±5.5nm respectively. The uptake of PF127/SDS micellar formulation incorporating Rhodamine 123 in MCF7 cancer cells was found to be higher (84.25%) than PF127/PC, PF127 and MTX i.e. 66.26%, 73.59% and 53% respectively. The in-vitro MTX release from PF127, PF127/SDS and PF127/PC polymeric micelles formulations was observed 69%, 69.5% and 66% at 12 h whereas 80.89%, 77.67% and 78.54% after 24 h respectively and reveals sustained release. MTX loaded PF127/SDS micelles showed high Partition coefficient and negative free energy of solubilization compared to PF127 and PF127/PC which signifies self-assembly behavior and thermodynamic stability towards dissociation to be higher. Conclusion: Finally concluded that MTX loaded PF127/SDS micelles act as a potential anticancer delivery system in comparison to PF127/PC and PF127 to combat against tumor cells by enhancing its cellular uptake targeting with sustained release pattern and reducing the thermodynamic instability. Thus, PF127/SDS micellar formulation can provide a useful alternative dosage form for intravenous administration of MTX.


2008 ◽  
Vol 3 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Zoran Maksimović ◽  
Marina Milenković ◽  
Dragana Vučićević ◽  
Mihailo Ristić

AbstractThis paper presents the results of a study on chemical composition and antimicrobial activity of Thymus pannonicus All. (Lamiaceae) essential oil from Vojvodina province (north of Serbia). The investigated oil was hydrodistilled from a flowering plant and analysed by GC and GC-MS. Fifty-three constituents were identified (>97% of total oil), with geranial (41.42%, w/w) and neral (29.61%, w/w) as the most prominent. The antimicrobial activity of the oil was evaluated using agar disc diffusion and broth microdilution method against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, two strains of Klebsiella pneumoniae and two strains of Candida albicans. The essential oil exhibited antimicrobial activity to varying degrees against all tested strains. The maximum activity of T. Pannonicus oil was observed against E. coli, S. aureus and both tested strains of C. Albicans (MIC = 50 µ/ml, each). Moderate activity was observed against P. aeruginosa and one of the tested strains of K. Pneumoniae (MIC = 200 µ/ml), while E. faecalis and the other strain of K. Pneumoniae expressed a higher degree of resistance (MIC > 200 µ/ml). This study confirms that essential oil of T. pannonicus possesses remarkable in vitro antimicrobial activity against several medicinally important pathogens. This is attributable to lemon-scented citral, a mixture of geranial and neral, which has well-documented antimicrobial activity against a range of bacteria and fungi.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1285
Author(s):  
Samira de Aquino Leite Fiordalisi ◽  
Luciana Aparecida Honorato ◽  
Shirley Kuhnen

Background: Aloe barbadensis Miller, also known as Aloe vera is a well-known phytotherapeutic, and parts of its leaves are used for a wide range of medicinal purposes. This study seeks to assess the in vitro antimicrobial and cytotoxic effects of leaf exudate (LE) from A. barbadensis leaves against Staphylococcus aureus and MAC-T bovine mammary epithelial cells. Methods: Seasonal LE samples were collected, and the effect on total phenolic and aloin contents was determined. Antimicrobial activity of LE was evaluated using the broth microdilution method, and toxicity to MAC-T cells was determined by MTT assay. Results: Samples collected during different seasons of the year showed a seasonal effect on the chemical profile of LE (P<0.05). However, despite these chemical variations, we found no differences in antimicrobial activity against S. aureus. For all studied samples, the minimum inhibitory concentration (MIC) was 1,000 µg/mL. Furthermore, we found an elevated cytotoxic effect of LE on MAC-T cells with a significant reduction in cellular viability at 7.8 µg/mL (P<0.05) and an IC50 of 91.89 µg/mL. Conclusions: Despite the antimicrobial effects of LE, the high toxicity for MAC-T cells suggests that it is unsuitable for intramammary use, but does have potential as a topical antimicrobial.


2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Kristina Ložienė ◽  
Juozas Labokas ◽  
Vaida Vaičiulytė ◽  
Jurgita Švedienė ◽  
Vita Raudonienė ◽  
...  

The study aimed to establish the chemical composition of fruit essential oils of M. gale and test their activities against the selected pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii), yeasts (Candida albicans, C. parapsilosis), fungi (Aspergillus fumigatus, A. flavus) and dermatophytes (Trichophyton rubrum, T. mentagrophytes). Fruit samples from natural (Western Lithuania) and anthropogenic (Eastern Lithuania) M. gale populations were studied separately. Essential oils were isolated from dried fruits by hydrodistillation and analysed by GC/FID and GC/MS methods; enantiomeric composition of α-pinene was established by chiral-phase capillary GC. Minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) of essential oils were determined using the broth microdilution method. Plants from the natural population with a humid marine climate accumulated significantly higher amounts of fruit essential oils (3.34±0.05%) than those from the anthropogenic population with a more continental climate (2.71±0.22%). In total, 39 volatiles including α-pinene (23.52–27.17%), 1,8-cineole (17.19–18.84%) and α-phellandrene (9.47–10.03%) as main compounds were identified. Chiral analysis demonstrated that (1S)-(–)-α-pinene prevailed over (1R)-(+)-α-pinene and amounted to 94.09–95.28% of all fraction of this monoterpene. The antimicrobial study in vitro indicated that C. parapsilosis, dermatophytes and Aspergillus fungi were more susceptible to fruit essential oils of M. gale, whereas E. coli and C. albicans were weakly inhibited even at the highest essential oil concentration. The strongest growth-inhibitory and bactericidal effect of sweet gale essential oil was established on S. aureus. This could be attributed to the major essential oil compounds with known antimicrobial activity, such as α-pinene, 1,8-cineole and a-phellandrene. Keywords: Myrica gale; essential oil; chemical compounds; terpenes; enantiomers; antimicrobial.


Author(s):  
Hussein K. Alkufi ◽  
Hanan J. Kassab

     Objective: The purpose of this study to develop and optimize nasal mucoadhesive in situ gel IG of sumatriptan ST (serotonin agonist) to enhance nasal residence time for migraine management.      Method: Cold method was used to prepare ST nasal in-situ gel, using thermosensitive polymers (poloxamer 407  and/or poloxamer 188) with a mucoadhesive polymer (hyaluronic acid HA) which were examined for gelation temperature and gelation time, pH, drug content, gel strength, spreadability, mucoadhesive force determination, viscosity,  in-vitro drug release, and the selected formula was subjected to ex-vivo permeation study and histological evaluation of the sheep mucosal tissue after application.     Results: The results showed that the formula IG7 prepared from poloxamer 407(19%), poloxamer188 (4%) and HA (0.5%)   had an optimum gelation temperature (32.66±1.52°C), gel  strength (43.66± 1.52 sec),  mucoadhesive force (8067.93± 746.45dyne\cm2), in-vitro drug release (95.98%) over 6hr, ex-vivo permeation study release (89.6%)  during the 6 h. study with no  histological or pathological change in the nasal sheep tissue.     Conclusion: The ease of administration via a nasal drop of ST coupled with less frequent administration and prolong drug release, will enhance patient compliance.


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