scholarly journals ELISA- and Activity Assay-Based Quantification of BMP-2 Released In Vitro Can Be Biased by Solubility in “Physiological” Buffers and an Interfering Effect of Chitosan

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 582
Author(s):  
Julius Sundermann ◽  
Steffen Sydow ◽  
Laura Burmeister ◽  
Andrea Hoffmann ◽  
Henning Menzel ◽  
...  

Chitosan nanogel-coated polycaprolactone (PCL) fiber mat-based implant prototypes with tailored release of bone morphogenic protein 2 (BMP-2) are a promising approach to achieve implant-mediated bone regeneration. In order to ensure reliable in vitro release results, the robustness of a commercially available ELISA for E. coli-derived BMP-2 and the parallel determination of BMP-2 recovery using a quantitative biological activity assay were investigated within a common release setup, with special reference to solubility and matrix effects. Without bovine serum albumin and Tween 20 as solubilizing additives to release media buffed at physiological pH, BMP‑2 recoveries after release were notably reduced. In contrast, the addition of chitosan to release samples caused an excessive recovery. A possible explanation for these effects is the reversible aggregation tendency of BMP-2, which might be influenced by an interaction with chitosan. The interfering effects highlighted in this study are of great importance for bio-assay-based BMP-2 quantification, especially in the context of pharmaceutical release experiments.

2019 ◽  
Vol 8 (3) ◽  
pp. 576-585

In the present study silver nanoparticles (AgNPs) have been synthesized through the cell-free extracts of the rooftop dwelling cyanobacterium Scytonema geitleri HKAR-12. UV-VIS spectroscopy, FTIR, X-ray diffraction, SEM and TEM were used for the determination of morphological, structural and optical properties of synthesized AgNPs. Extracts of Scytonema geitleri HKAR-12 have the ability to reduce AgNO3 to Ag0. Sharp peak at 422 nm indicated the rapid synthesis of AgNPs. FTIR results showed the presence of different groups responsible for the reduction of AgNO3 to AgNPs. XRD pattern confirmed the crystalline nature of AgNPs. SEM showed the bead shape structure of AgNPs. TEM confirmed the actual size of AgNPs to be ranging between 9-17 nm. AgNPs showed antibacterial activity against Pseudomonas aeruginosa, Escherichia coli strain1 and E. coli strain 2 and 11 μg/mL of AgNPs effectively inhibited the growth of MCF-7 cells. Hence, Scytonema geitleri HKAR-12, isolated from the rooftop could serve as a desirable biological candidate for convenient and cheap production of AgNPs having antimicrobial and anti-cancerous properties.


2021 ◽  
Vol 11 (5) ◽  
pp. 13089-13101

In this study, a sustainable HPLC-UV-DAD method was developed and validated for the determination of allopurinol in tablets and optimization of the dissolution test using factorial design. The separation of the analyte from the sample matrix was achieved in 3.01 minutes in a C8 column (4.6 mm X 150 mm X 5 μm), using mobile phase 0.1 mol L-1 HCl (25%) + ethanol (50%) + ultrapure water (25%) by UV detection at 249 nm. The method presented satisfactory analytical parameters of validation (specificity, selectivity, linearity, stability, precision, accuracy, and robustness), showing no matrix effects. The dissolution test was optimized by complete factorial design 23 and, the optimal conditions were: HCl 0.001 mol L-1, apparatus II (paddle) and 75 rpm. The analytical procedures and dissolution tests were applied to allopurinol tablets marketed in Bahia, Brazil, to evaluate the dissolution studies. The pharmaceuticals had similar dissolution profiles and first-order dissolution kinetics. This new and sustainable HPLC-UV-DAD method is friendly to the environment and can be used for the routine pharmaceutical analysis of allopurinol in fixed dosage forms.


Author(s):  
SAMIULLAH ◽  
SYED UMER JAN ◽  
RAHMAN GUL ◽  
SYED JALALUDIN ◽  
ASMATHULLAH

Objective: This study was conducted to design a transdermal dosage form of pseudoephedrine HCL and to evaluate its release under controlled rates for sustained transdermal delivery of Pseudoephedrine. Methods: Transdermal patches were prepared by the casting evaporation method. Utilizing eudragit RL100. Patches were characterized by physical appearance, moisture content, thickness, weight variation, folding endurance, tensile strength and stability studies. Fourier transform infrared spectroscopic studies (FTIR), differential scanning calorimetry analysis (SCA) and XRD studies. Four different permeation enhancer (Tween 20, thymus oil, castor oil and eucalyptus oil) was employed. In vitro release of drugs was done in the dissolution paddle apparatus. Release studies were performed in distilled water at 37 °C. Scanning electron microscope studies were performed before and after the drug. Results: Transdermal patches with enhancers were formulated successfully with a concentration of 1% (W/V). The patches indicated stable physicochemical characteristics. FTIR, SCA and XRD Studies showed that there were no physical and chemical interactions between excipients and drugs. Results of in vitro permeation studies showed that enhancers used in this study increased drug released. The enhancers showed faster released than no enhancer. This arrangement can be shown as Tween>Eucalyptus oil>Thymus oil and castor oil. Formulation F2 is optimized among all formulations showed an 83.3% release. Conclusion: Transdermal patches of pseudoephedrine were successfully developed by using pseudo epinephrine HCL. These patches proved to be very useful for therapeutic purposes in the pharmaceutical industry without making the patients unconscious, unlike the trivial methods of treatment.


Author(s):  
PAMU SANDHYA

Objective: The main objective of this study was to preparation and evaluation of efavirenz (EFV) to enhance its solubility and dissolution rate by self-emulsifying drug delivery system. Methods: EFV self-emulsifying drug delivery systems (SNEDDS) were formulated using different oils, surfactant, and co-surfactant. Peceol, Tween 20, and Capmul MCM were used as oil, surfactant, and co-surfactant, respectively, followed by the evaluation by the performance of different tests such as visual observation, solubility studies, thermodynamic stability study, transmittance studies, drug content, and in-vitro release study. Results: Fourier-transform infrared studies revealed negligible drug and polymer interaction. From the phase diagram, it was observed that self-emulsifying region was enhanced with increasing surfactant and co-surfactant concentrations with oil. F13 was selected as optimized formulation on the basis of physicochemical parameters, particle size, and in-vitro dissolution studies with the release of 98.39±5.10% drug in 1 hour. The optimized formulation size was found to be 156.7 nm as mean droplet size and Z-Average of 808.6 nm with -18.3 mV as zeta potential. Conclusion: The study demonstrated that SNEDDS was a promising strategy to enhance the dissolution rate of EFV by improving solubility.


2013 ◽  
Vol 68 (5-6) ◽  
pp. 191-197 ◽  
Author(s):  
Birkan Açıkgöz ◽  
İskender Karaltı ◽  
Melike Ersöz ◽  
Zeynep M. Coşkun ◽  
Gülşah Çobanoğlu ◽  
...  

The present study explores the antimicrobial activity and cytotoxic effects in culture assays of two fruticose soil lichens, Cladonia rangiformis Hoffm. and Cladonia convoluta (Lamkey) Cout., to contribute to possible pharmacological uses of lichens. In vitro antimicrobial activities of methanol and chloroform extracts against two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), two Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus), and the yeast Candida albicans were examined using the paper disc method and through determination of minimal inhibitory concentrations (MICs). The data showed the presence of antibiotic substances in the chloroform and the methanol extracts of the lichen species. The chloroform extracts exhibited more signifi cant antimicrobial activity than the methanol extracts. However, a higher antifungal activity was noted in the methanol extract of C. rangiformis. The maximum antimicrobial activity was recorded for the chloroform extract of C. convoluta against E. coli. The cytotoxic effects of the lichen extracts on human breast cancer MCF-7 cells were evaluated by the trypan blue assay yielding IC50 values of ca. 173 and 167 μg/ml for the extracts from C. rangiformis and C. convoluta, respectively.


Author(s):  
EMAN A. MAZYED ◽  
SHERIN ZAKARIA

Objective: The present investigation aims to formulate and evaluate proniosomes of clopidogrel bisulphate for improving its dissolution characteristics. Methods: The slurry method was used for the preparation of proniosomes of clopidogrel using cholesterol, sorbitan monostearate (Span 60) and maltodextrin as a carrier. Clopidogrel proniosomes were evaluated for their entrapment efficiency and in vitro drug release. The best formula (F1) that achieved maximum drug release was further evaluated by measurement of the angle of repose, morphological examination, determination of vesicle size, determination of zeta potential, Fourier transform infrared spectroscopy and differential thermal analysis. The in vivo behavior of the selected proniosomal formula (F1) was studied by measuring the antiplatelet activity in adult male mice. Results: The entrapment efficiency of clopidogrel proniosomes was in the range of 83.04±1.99 to 90.14±0.30. % drug released from proniosomal formulations was in the range of 79.73±0.35 to 97.70±1.10 % within 4 h. Clopidogrel proniosomes significantly enhanced the in vitro release of clopidogrel compared with the plain drug that achieved 61.77±2.22 % drug release. F1 significantly (p ≤ 0.001) increased the bleeding time and bleeding volume and significantly (p ≤ 0.05) prolonged prothrombin time and decreased prothrombin activity and increased the international normalized ratio (INR) compared to plain clopidogrel. Conclusion: The present investigation introduced proniosomes as a promising carrier for clopidogrel that could enhance its dissolution and pharmacological effect.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Rashmin B. Patel ◽  
Mrunali R. Patel ◽  
Kashyap K. Bhatt ◽  
Bharat G. Patel

A new, simple, and rapid high-performance thin-layer chromatographic method was developed and validated for quantitative determination of Carbamazepine. Carbamazepine was chromatographed on silica gel 60 F254 TLC plate using ethyl acetate-toluene-methanol (5.0 + 4.0 + 1.0 v/v/v) as mobile phase. Carbamazepine was quantified by densitometric analysis at 285 nm. The method was found to give compact spots for the drug (Rf=0.47 ± 0.01). The linear regression analysis data for the calibration plots showed good linear relationship with r2=.9995 in the concentration range 100–600 ng/spot. The method was validated for precision, recovery, repeatability, and robustness as per the International Conference on Harmonization guidelines. The minimum detectable amount was found to be 16.7 ng/spot, whereas the limit of quantitation was found to be 50.44 ng/spot. Statistical analysis of the data showed that the method is precise, accurate, reproducible, and selective for the analysis of Carbamazepine. The method was successfully employed for the estimation of equilibrium solubility, quantification of Carbamazepine as a bulk drug, in commercially available preparation, and in-house developed mucoadhesive microemulsion formulations and solution.


Pharmacia ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 49-54
Author(s):  
Krassimira Yoncheva ◽  
Nadia Hristova-Avakumova ◽  
Vera Hadjimitova ◽  
Trayko Traykov ◽  
Petar Petrov

The study was focused on the evaluation of two copolymers as micellar carriers for kaempferol delivery. The copolymers comprised identical hydrophilic blocks of poly(2-(dimethylamino)ethyl methacrylate and different hydrophobic blocks of either poly(ε-caprolactone) (PDMAEMA9-b-PCL70-b-PDMAEMA9) or poly(propylene oxide) (PDMAEMA13-b-PPO69-b-PDMAEMA13). The calculation of Flory-Huggins parameters and determination of encapsulation efficiency showed that PDMAEMA-b-PCL-b-PDMAEMA copolymer possessed higher capacity for kaempferol loading. The diameter of the micelles before and after lyophilization was not changed, suggesting that the micelles could be lyophilized and redispersed before administration. The in vitro release of kaempferol from PDMAEMA-b-PPO-b-PDMAEMA micelles was faster than the release from PDMAEMA-b-PCL-b-PDMAEMA micelles, probably due to the higher affinity of kaempferol to this copolymer. Further, the higher affinity resulted in a retention of antioxidant activity of kaempferol in the presence of DPPH and KO2 radicals. Thus, PDMAEMA-PCL-PDMAEMA was considered more appropriate carrier because of the higher encapsulation efficiency and preservation of antioxidant activity of the drug.


2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Yalda Mirzaei ◽  
Kerstin Hagemeister ◽  
Martina Hüffel ◽  
Timo Schwandt ◽  
René H. Tolba ◽  
...  

Background. Tissue glues can minimize treatment invasiveness, mitigate the risk of infection, and reduce surgery time; ergo, they have been developed and used in surgical procedures as wound closure devices beside sutures, staples, and metallic grafts. Regardless of their structure or function, tissue glues should show an acceptable microbial barrier function before being used in humans. This study proposes a novel in vitro method using Escherichia coli Lux and bioluminescence imaging technique to assess the microbial barrier function of tissue glues. Different volumes and concentrations of E. coli Lux were applied to precured or cured polyurethane-based tissue glue placed on agar plates. Plates were cultured for 1 h, 24 h, 48 h, and 72 h with bioluminescence signal measurement subsequently. Herein, protocol established a volume of 5 μL of a 1 : 100 dilution of E. coli Lux containing around 2 × 10 7  CFU/mL as optimal for testing polyurethane-based tissue glue. Measurement of OD600nm, determination of CFU/mL, and correlation with the bioluminescence measurement in p/s unit resulted in a good correlation between CFU/mL and p/s and demonstrated good reproducibility of our method. In addition, this in vitro method could show that the tested polyurethane-based tissue glue can provide a reasonable barrier against the microbial penetration and act as a bacterial barrier for up to 48 h with no penetration and up to 72 h with a low level of penetration through the material. Overall, we have established a novel, sensitive, and reproducible in vitro method using the bioluminescence imaging technique for testing the microbial barrier function of new tissue glues.


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