scholarly journals Ophthalmic In Situ Gels with Balsam Poplar Buds Extract: Formulation, Rheological Characterization, and Quality Evaluation

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 953
Author(s):  
Monika Stanciauskaite ◽  
Mindaugas Marksa ◽  
Liudas Ivanauskas ◽  
Kristina Perminaite ◽  
Kristina Ramanauskiene

Balsam poplar buds are a raw material with a high content of polyphenols. Various polyphenols are known for their anti-inflammatory and antioxidant properties. In this study, an aqueous extract of balsam poplar buds was prepared in order to use environmentally friendly and non-aggressive solvents. The aqueous extract was lyophilized, and a 1% aqueous solution of lyophilized balsam poplar buds extract (L1) was prepared. L1 solution was used as a source of polyphenols for the production of ophthalmic in situ gels, so as to develop a product featuring antioxidant properties. Poloxamer 407 (P407) and hydroxypropyl methylcellulose (HPMC) were selected as gelling agents for the in situ gels. In order to select the formulations with the best conditions of use, formulations of different polymer concentrations (P407—10%, 12%, 15%; HPMC—0.5%, 0.75%) were prepared, choosing the same amount of the active polyphenol source L1. The physicochemical properties, rheological parameters, stability, and irritant effect on the rabbit corneal cell line (SIRC) were evaluated. Formulations in which P407 and HMPC concentrations were 10/0.75% and 12%/0.75% reached a gelation point close to the ocular surface temperature; the gels remained stable for 30 days and did not cause an irritant effect on the SIRC cell line.

2018 ◽  
Vol 10 (4) ◽  
pp. 153 ◽  
Author(s):  
Fadia Yassir Al-bazzaz ◽  
Myasar Al-kotaji

Objective: This work aims to formulate and evaluate an ophthalmic in-situ gel of ciprofloxacin hydrochloride (HCl) using poloxamer 407 (P407) as a gelling agent and hydroxypropyl methylcellulose (HPMC) as a viscosity modifier. The objective of this work was to prolong the contact time as the in-situ gel will be converted into a gel upon contact with the cul-de-sac. Methods: Ciprofloxacin HCl ophthalmic in-situ gel was prepared by utilizing (P407) as a temperature-dependent polymer while hydroxypropyl methylcellulose was used as a viscosity modifier. The system was evaluated for physical appearance, pH, drug content, sterility, irritancy and stability. In addition, gelation temperature and a viscosity at different shear rates and different temperatures were studied. The compatibility of the polymer with ciprofloxacin was studied by using fourier transform infrared spectroscopy (FTIR). The in vitro release of the drug was also evaluated and supported by a preliminary in vivo test.Results: The results showed that the prepared formulas were clear, with acceptable pH and the drug contents were within the acceptable limits. FTIR results detected no incompatibility between poloxamer 407 and ciprofloxacin HCl. Notably, the viscosity of the system showed a pseudoplastic behaviour where a reduction in viscosity upon increasing the shear rate was observed. The in vitro release study confirmed the prolongation of the release of the optimized formula (F6) up to 8 h. Upon application of F6 into eyes of rabbits there was no irritancy. In addition, in vivo elimination study showed a prolonged contact for the in-situ gel in comparison with the rapid clearance of eye drop. Stability study indicated the stability of the optimized formula (F6). Conclusion: The prepared optimized formula (F6) represents a successful, safe, stable and prolonged release in-situ gel formula of ciprofloxacin.


Author(s):  
INSAN SUNAN KURNIAWANSYAH ◽  
TAOFIK RUSDIANA ◽  
HURIYATUS TSANIYAH ◽  
HANDRIAN RAMOKO ◽  
HABIBAH A. WAHAB ◽  
...  

Objective: The objective of this study was to find the best base mixture composition (poloxamer 407 and HPMC) of chloramphenicol in situ gel formula based on in vitro property (Cumulative amount of drug release). Methods: The in vitro diffusion of chloramphenicol in situ gel study was carried out using franz diffusion cells to know the effect of the Critical Process Parameters (CPPs) as independent variables (poloxamer 407 and hydroxypropyl methylcellulose (HPMC)) on the Critical Quality Attribute (CQA) as dependent variable (cumulative amount of drug release) with 22 factorial design. Results: 22 factorial design of chloramphenicol in situ gel yielded 4 variations of poloxamer 407 and HPMC bases component in %w/v as follows, F1 (5:0.45), F2 (10:0.45) F3 (5:1) and F4 (10:1). The amount of drug release results from in vitro dissolution assay were 30.60% (F1), 45.64% (F2), 58.30% (F3), and 22.50%) (F4). Conclusion: Formula 3 (F3) was considered as the best formula component in terms of in vitro assay of chloramphenicol in situ gel with a desirability value of 0.58.


2020 ◽  
Vol 10 (03) ◽  
pp. 109-115
Author(s):  
Shreya Udaya ◽  
Nishith Babu ◽  
Dechamma Pandyanda Nanjappa ◽  
Krithika Kalladka ◽  
Gunimala Chakraborty ◽  
...  

Abstract Objective This study was aimed at evaluating the toxicity and the antioxidant property of Cassia fistula stem bark extracts in zebrafish. Materials and Methods Crude aqueous and ethanol extracts of C. fistula stem bark were obtained following a standard solvent-based extraction method. The toxicity of these extracts on zebrafish embryonic development was determined and the LC50 values were calculated. Finally, the antioxidant property of C. fistula stem bark extracts was determined in arsenic-induced oxidative stress models of zebrafish. Results The aqueous extract of C. fistula stem bark showed a slightly larger LC50 value (213.6 ppm) compared with the ethanol extract (LC50 = 63.5 ppm), suggesting a lower toxicity of the aqueous extract. A significant reduction of reactive oxygen species (ROS) signal was observed in arsenic-exposed embryos treated with the aqueous extract, but not the ethanol extract, indicating that the antioxidant activity is present only in the aqueous extract of C. fistula stem bark. Conclusion Identification of antioxidants from natural sources is desirable because of increasing safety concerns associated with synthetic antioxidants. This study demonstrated that aqueous extract from C. fistula stem bark possesses antioxidant properties, which can be further characterized for mechanism of action and potential applications.


Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 178
Author(s):  
Souhail Maazioui ◽  
Abderrahim Maazouz ◽  
Fayssal Benkhaldoun ◽  
Driss Ouazar ◽  
Khalid Lamnawar

Phosphate ore slurry is a suspension of insoluble particles of phosphate rock, the primary raw material for fertilizer and phosphoric acid, in a continuous phase of water. This suspension has a non-Newtonian flow behavior and exhibits yield stress as the shear rate tends toward zero. The suspended particles in the present study were assumed to be noncolloidal. Various grades and phosphate ore concentrations were chosen for this rheological investigation. We created some experimental protocols to determine the main characteristics of these complex fluids and established relevant rheological models with a view to simulate the numerical flow in a cylindrical pipeline. Rheograms of these slurries were obtained using a rotational rheometer and were accurately modeled with commonly used yield-pseudoplastic models. The results show that the concentration of solids in a solid–liquid mixture could be increased while maintaining a desired apparent viscosity. Finally, the design equations for the laminar pipe flow of yield pseudoplastics were investigated to highlight the role of rheological studies in this context.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 646
Author(s):  
Gábor Katona ◽  
Bence Sipos ◽  
Mária Budai-Szűcs ◽  
György Tibor Balogh ◽  
Szilvia Veszelka ◽  
...  

The aim of this study was to develop an intranasal in situ thermo-gelling meloxicam-human serum albumin (MEL-HSA) nanoparticulate formulation applying poloxamer 407 (P407), which can be administered in liquid state into the nostril, and to increase the resistance of the formulation against mucociliary clearance by sol-gel transition on the nasal mucosa, as well as to improve drug absorption. Nanoparticle characterization showed that formulations containing 12–15% w/w P407 met the requirements of intranasal administration. The Z-average (in the range of 180–304 nm), the narrow polydispersity index (PdI, from 0.193 to 0.328), the zeta potential (between −9.4 and −7.0 mV) and the hypotonic osmolality (200–278 mOsmol/L) of MEL-HSA nanoparticles predict enhanced drug absorption through the nasal mucosa. Based on the rheological, muco-adhesion, drug release and permeability studies, the 14% w/w P407 containing formulation (MEL-HSA-P14%) was considered as the optimized formulation, which allows enhanced permeability of MEL through blood–brain barrier-specific lipid fraction. Cell line studies showed no cell damage after 1-h treatment with MEL-HSA-P14% on RPMI 2650 human endothelial cells’ moreover, enhanced permeation (four-fold) of MEL from MEL-HSA-P14% was observed in comparison to pure MEL. Overall, MEL-HSA-P14% can be promising for overcoming the challenges of nasal drug delivery.


Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 70
Author(s):  
Lourdes Mateos-Hernández ◽  
Natália Pipová ◽  
Eléonore Allain ◽  
Céline Henry ◽  
Clotilde Rouxel ◽  
...  

Neuropeptides are small signaling molecules expressed in the tick central nervous system, i.e., the synganglion. The neuronal-like Ixodes scapularis embryonic cell line, ISE6, is an effective tool frequently used for examining tick–pathogen interactions. We detected 37 neuropeptide transcripts in the I. scapularis ISE6 cell line using in silico methods, and six of these neuropeptide genes were used for experimental validation. Among these six neuropeptide genes, the tachykinin-related peptide (TRP) of ISE6 cells varied in transcript expression depending on the infection strain of the tick-borne pathogen, Anaplasma phagocytophilum. The immunocytochemistry of TRP revealed cytoplasmic expression in a prominent ISE6 cell subpopulation. The presence of TRP was also confirmed in A. phagocytophilum-infected ISE6 cells. The in situ hybridization and immunohistochemistry of TRP of I. scapularis synganglion revealed expression in distinct neuronal cells. In addition, TRP immunoreaction was detected in axons exiting the synganglion via peripheral nerves as well as in hemal nerve-associated lateral segmental organs. The characterization of a complete Ixodes neuropeptidome in ISE6 cells may serve as an effective in vitro tool to study how tick-borne pathogens interact with synganglion components that are vital to tick physiology. Therefore, our current study is a potential stepping stone for in vivo experiments to further examine the neuronal basis of tick–pathogen interactions.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jigang Wang ◽  
Jianbin Zhang ◽  
Chong-Jing Zhang ◽  
Yin Kwan Wong ◽  
Teck Kwang Lim ◽  
...  

2014 ◽  
Vol 45 (2) ◽  
pp. 323-328 ◽  
Author(s):  
Fernanda Robert de Mello ◽  
Claudia Bernardo ◽  
Caroline Odebrecht Dias ◽  
Luciano Gonzaga ◽  
Edna Regina Amante ◽  
...  

Pitaya peel can be used as a raw material for betalains extraction. The aim of this research was to quantify phenolic compounds, antioxidant activity and betalains on pitaya peel. Furthermore, evaluate the betalains stability against various pH conditions and exposure time of heating. The results showed that pitaya peel contains phenolic compounds and presented antioxidant activity. Moreover it showed high concentration of betalains (101.04mg equivalent to betanin. 100g-1) which were stable over a wide pH range (3.2 - 7.0) and were resistant to heating (100oC) up to 10 minutes at pH range from 3.7 to 5.5. Therefore, pitaya peel is a promising source of betalains which can be applied as a natural colorant for food.


2014 ◽  
Vol 1020 ◽  
pp. 423-428 ◽  
Author(s):  
Eva Hrubesova ◽  
Marek Mohyla

The paper deals with the back analysis method in geotechnical engineering, that goal is evaluation the more objective and reliable parameters of the rock mass on the basis of in-situ measurements. Stress, deformational, strength and rheological parameters of the rock mass are usually determined by some inaccuracies and errors arising from the complexity and variability of the rock mass. This higher or lower degree of imprecision is reflected in the reliability of the mathematical modelling results. The paper presents the utilization of direct optimization back analysis method, based on the theory of analytical functions of complex variable and Kolosov-Muschelischvili relations, to the evaluation of initial stress state inside the rock massif.


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