scholarly journals Feasibility Study and Direct Extraction of Endogenous Free Metallic Cations Combining Hemodialysis and Chelating Polymer

Author(s):  
Marco Natuzzi ◽  
Coralie Grange ◽  
Thomas Gréa ◽  
Thomas Brichart ◽  
Axel Aigle ◽  
...  

Abstract In this article, we report the conception and the use of dialysis based medical device for extraction of metals. The medical device is obtained by addition in the dialysate of a functionnalized chitosan that can chelate endogenous metals like iron or copper. The water soluble functionnalized chitosan is obtained after controlled reacetylation and addition of DOTAGA. Due to the high mass of chitosan, the polymer cannot cross through the membrane and the metals are trapped in the dialysate during hemodialysis. Copper captation has been evaluated in vitro using an hemodialysis protocol. Feasibility study has been performed on healthy sheep showing no acute toxicity of the whole procedure and first insights of metallic extraction even on healthy animals.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marco Natuzzi ◽  
Coralie Grange ◽  
Thomas Gréa ◽  
Thomas Brichart ◽  
Axel Aigle ◽  
...  

AbstractIn this article, we report the conception and the use of dialysis-based medical device for the extraction of metals. The medical device is obtained by addition in the dialysate of a functionalized chitosan that can chelate endogenous metals like iron or copper. This water-soluble functionalized chitosan is obtained after controlled reacetylation and grafting of DOTAGA. Due to the high mass of chitosan, the polymer cannot cross through the membrane and the metals are trapped in the dialysate during hemodialysis. Copper extraction has been evaluated in vitro using an hemodialysis protocol. Feasibility study has been performed on healthy sheep showing no acute toxicity througout the entire dialysis procedure and first insights of metallic extraction even on healthy animals.


Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website


Author(s):  
Lê Thanh Long ◽  
Nguyễn Văn Toản ◽  
Nguyễn Văn Huế ◽  
Trang Sĩ Trung ◽  
Vũ Ngọc Bội

Chủng D1 phân lập từ các mẫu chuối có vết bệnh thán thư điển hình được sử dụng để nghiên cứu khả năng kháng nấm của chitosan hoà tan trong nước (Water-soluble chitosan_WSC) ở điều kiện in vitro. Kết quả phân tích trình tự gen mã hoá 28S rRNA của chủng D1 cho thấy tương đồng trình tự cao với các trình tự tương ứng của loài Colletotrichum musae và được ký hiệu là Colletotrichum musae D1. Kết quả các thí nghiệm đều cho thấy C. musae D1 rất nhạy cảm với WSC, hiệu lực ức chế tăng khi tăng nồng độ WSC xử lý ở điều kiện in vitro. Trên môi trường PDA, nồng độ 1,6% WSC ức chế hoàn toàn sự sinh trưởng của sợi nấm C. musae D1, nồng độ ức chế 50% (PIRG50) và nồng độ ức chế tối thiểu 90% (MIC90) tương ứng với nồng độ WSC 0,28% và 0,88%. Trong môi trường PDB, giá trị IC50 và MIC90 tương ứng là 0,11% và 0,43% và sự phát triển của sợi nấm C. musae D1 bị ức chế hoàn toàn ở nồng độ 0,8%. WSC không chỉ ức chế sự nảy mầm mà còn gây biến đổi bất thường bào tử nấm khi quan sát trên kính hiển vi.


Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.


Author(s):  
Prakash Goudanavar ◽  
Ankit Acharya ◽  
Vinay C.H

Administration of an antiviral drug, acyclovir via the oral route leads to low and variable bioavailability (15-30%). Therefore, this research work was aimed to enhance bioavailability of acyclovir by nanocrystallization technique. The drug nanocrystals were prepared by anti-solvent precipitation method in which different stabilizers were used. The formed nanocrystals are subjected to biopharmaceutical characterization including solubility, particle size and in-vitro release. SEM studies showed nano-crystals were crystalline nature with sharp peaks. The formulated drug nanocrystals were found to be in the range of 600-900nm and formulations NC7 and NC8 showed marked improvement in dissolution velocity when compared to pure drug, thus providing greater bioavailability. FT-IR and DSC studies revealed the absence of any chemical interaction between drug and polymers used. 


Author(s):  
Sudarshan Singh ◽  
S S Shyale ◽  
P Karade

The aim of this study was to design orally disintegrating tablet (ODT) of Lamotrigine. It is an Antiepileptic drug which is widely used in epilepsy. It is also used in simple and complex partial seizures and secondary generalized tonic-clonic seizures. It is poorly water soluble drug (0.46 mg/ml). Thus, an attempt was made to enhance the water solubility by complexation with β-cyclodextrin (1:1 molar ratios). The orally disintegrating tablet of lamotrigine was prepared by direct compression method using different concentration of superdisintegrants such as Sodium starch glycollate, croscarmellose sodium by sublimating agent such as camphor. The formulations were evaluated for weight variation, hardness, friability, drug content, wetting time, in vitro disintegration time and in vitro dissolution studies. The prepared tablets were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The disintegration time for the complexed tablets prepared by different concentration of superdisintegrants was found to be in range of 32.54 ± 0.50 to 55.12 ± 0.57 sec and wetting time of the formulations was found to be in range of 28.47 ± 0.67 to 52.19 ± 0.72 sec. All the formulation showed almost 100 percent of drug release within 15 min. Among all the formulation F6 and F7 prepared with 18% croscarmellose sodium and camphor shows faster drug release, respectively 10 min, F6 gives good result for disintegration time, drug release, wetting time and friability. Further formulations were subjected to stability testing for 30 days at temperature of 40 ± 5 ºC/75 ± 5 %RH. Tablets showed no appreciable changes with respect to physical appearance, drug content, disintegration time and dissolution profiles. Results were statistically analyzed by one-way ANOVA at a p < 0.05. It was found that, the data at any point of time are significant at p < 0.05.


2020 ◽  
Vol 17 ◽  
Author(s):  
Bingwei Wang ◽  
Jianping Liu ◽  
Zhenghua Li ◽  
Yulong Xia ◽  
Shuangshuang Zhang ◽  
...  

Background: At present, there were numerous researches on the migration of components in tablets and granules, the investigation in the pharmaceutical literatrue concerning the effect of drying rate on the migration of water-soluble components of pellets was limited. Temperature and relative humidity (RH) were crucial parameters during the drying process which was an essential step in the preparation of pellets via wet extrusion/spheronization. To quantify these variables, the water loss percentage of pellets per minute was defined as drying rate. Objective: The study aimed to investigate the influence of drying rate on the migration of water-soluble components in wet pellets and the potential migrated mechanism. Methods: The pellets containing tartrazine as a water-soluble model drug and microcrystalline cellulose as a matrix former were prepared by extrusion/spheronization and dried at four different drying temperature and relative humidity. Afterward, the extent of migrated tartrazine was assessed regarding appearance, in-vitro dissolution test, Differential Scanning Calorimetry, X-Ray Powder Diffraction, Attenuated total reflectance Fourier transform infrared spectroscopy and Confocal Raman Mapping. Results: Results demonstrated that red spots of tartrazine appeared on the surface of pellets and more than 40% tartrazine were burst released within 5 minutes when pellets dried at 60℃/RH 10%. While pellets dried at 40℃/RH 80%, none of these aforementioned phenomena was observed. Conclusion: In conclusion, the faster drying rate was, the more tartrazine migrated to the exterior of pellets. Adjusting drying temperature and relative humidity appropriately could inhibit the migration of water-soluble components within wet extrusion/spheronization pellets.


2018 ◽  
Vol 18 (4) ◽  
pp. 365-371 ◽  
Author(s):  
Denis V. Mishchenko ◽  
Margarita E. Neganova ◽  
Elena N. Klimanova ◽  
Tatyana E. Sashenkova ◽  
Sergey G. Klochkov ◽  
...  

Background: Anti-tumor effect of hydroxamic acid derivatives is largely connected with its properties as efficient inhibitors of histone deacetylases, and other metalloenzymes involved in carcinogenesis. Objective: The work was aimed to (i) determine the anti-tumor and chemosensitizing activity of the novel racemic spirocyclic hydroxamic acids using experimental drug sensitive leukemia P388 of mice, and (ii) determine the structure-activity relationships as metal chelating and HDAC inhibitory agents. Method: Outbreed male rat of 200-220 g weights were used in biochemical experiments. In vivo experiments were performed using the BDF1 hybrid male mice of 22-24 g weight. Lipid peroxidation, Fe (II) -chelating activity, HDAC fluorescent activity, anti-tumor and anti-metastatic activity, acute toxicity techniques were used in this study. Results: Chemosensitizing properties of water soluble cyclic hydroxamic acids (CHA) are evaluated using in vitro activities and in vivo methods and found significant results. These compounds possess iron (II) chelating properties, and slightly inhibit lipid peroxidation. CHA prepared from triacetonamine (1a-e) are more effective Fe (II) ions cheaters, as compared to CHA prepared from 1- methylpiperidone (2a-e). The histone deacetylase (HDAC) inhibitory activity, lipophilicity and acute toxicity were influenced by the length amino acids (size) (Glycine < Alanine < Valine < Leucine < Phenylalanine). All compounds bearing spiro-N-methylpiperidine ring (2a-e) are non-toxic up to 1250 mg/kg dose, while compounds bearing spiro-tetramethylpiperidine ring (1a-e) exhibit moderate toxicity which increases with increasing lipophility, but not excite at 400 mg/kg. Conclusion: It was shown that the use of combination of non-toxic doses of cisplatin (cPt) or cyclophosphamide with CHA in most cases result in the appearance of a considerable anti-tumor effect of cytostatics. The highest chemosensitizing activity with respect to leukemia Р388 is demonstrated by the CHA derivatives of Valine 1c or 2c.


2020 ◽  
Vol 15 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Vikas Jhawat ◽  
Gandhi Sivaraman ◽  
Om Prakash Sunnapu ◽  
Ramya Krishna Nakkala ◽  
...  

Background: Venlafaxine HCl is a selective serotonin reuptake inhibitor which is given in the treatment of depression. The delivery of the drug at a controlled rate can be of great importance for prolonged effect. Objective: The objective was to prepare and optimize the controlled release core in cup matrix tablet of venlafaxine HCl using the combination of hydrophilic and hydrophobic polymers to prolong the effect with rate controlled drug release. Methods: The controlled release core in cup matrix tablets of venlafaxine HCl were prepared using HPMC K5, K4, K15, HCO, IPA, aerosol, magnesium sterate, hydrogenated castor oil and micro crystalline cellulose PVOK-900 using wet granulation technique. Total ten formulations with varying concentrations of polymers were prepared and evaluated for different physicochemical parameters such FTIR analysis for drug identification, In-vitro drug dissolution study was performed to evaluate the amount of drug release in 24 hrs, drug release kinetics study was performed to fit the data in zero order, first order, Hixson–crowell and Higuchi equation to determine the mechanism of drug release and stability studies for 3 months as observed. Results: The results of hardness, thickness, weight variation, friability and drug content study were in acceptable range for all formulations. Based on the In vitro dissolution profile, formulation F-9 was considered to be the optimized extending the release of 98.32% of drug up to 24 hrs. The data fitting study showed that the optimized formulation followed the zero order release rate kinetics and also compared with innovator product (flavix XR) showed better drug release profile. Conclusion: The core-in-cup technology has a potential to control the release rate of freely water soluble drugs for single administration per day by optimization with combined use of hydrophilic and hydrophobic polymers.


2020 ◽  
Vol 6 (2) ◽  
pp. 155-169
Author(s):  
Neeraj Panihar ◽  
Neeru Vasudeva ◽  
Sunil Sharma ◽  
Babu Lal Jangir

Background: Fagopyrum esculentum Moench. is a herb consumed as food and has medicinal value. It is a rich source of bioactive nutrients which cure and prevent many ailments. Traditionally, it is used to treat hypertension, diabetes, constipation, cancer etc. Methods and Objective: Present work illustrates morphological, microscopic and physicochemical parameters of Fagopyrum esculentum seeds as per WHO guidelines, in vitro antioxidant activity; assessed by DPPH scavenging method, hydrogen peroxide scavenging assay and β-carotene linoleic acid bleaching method and study of lipid lowering potential of the ethyl acetate and ethanol extract of seeds on normal diet fed Wistar rats. Results: Morphological studies delineated the triangular shape, dark brown colour, 8 mm length and 6 mm width of the seed. The microscopic examination of the transverse section of seed depicted features like testa or pericarp (seed coat), the endosperm, embryo and sclerenchyma cells. Study of physiochemical parameters exhibited 0.3±0.02% of foreign matter and 1.44±0.51% crude fibre content. Total ash, acid insoluble ash and water soluble ash value were 6.7±1.7%, 1.9±0.23% and 3.9± 0.31% respectively. Alcohol soluble and water soluble extractive value came out to be 65.02± 3.21 mg/g and 12.7±1.24 mg/g respectively. Foaming index was less than 100, swelling index was found to be 0.5±0.01 ml/g. Loss on drying was 4.02±1.27%. Phytochemical screening of ethyl acetate and ethanol extract revealed the presence of alkaloids, carbohydrates, phenolic compounds, phytosterols and flavonoids. Trace amount of heavy metals (arsenic, cadmium, lead, mercury) were determined by atomic absorption spectrophotometer. Pesticide residue analysis confirmed the presence of nontoxic pesticides like dimethipin, hymexazol, phenothrin-2, methoprene, triadimenol, prohydrojasmon- 1, jasmolin ii, triademinol, jasmolin i, prohydrojasmone i, cyromazine in both the extracts by gc-ms spectrometer. The ethyl acetate and ethanol extract has shown significant in-vitro antioxidant activities demonstrated by the DPPH method (IC50 = 94.37±2.51 and 216.04±4.39 μg/ml respectively), hydrogen peroxide scavenging assay (IC50 = 83.72±3.72 and 193.47±5.05 µg/ml respectively) and β-carotene bleaching method (IC50 = 100.67±4.01 and 205.39±2.89 µg/ml respectively). Lipid lowering study performed on Wistar rats demonstrated a significant (p<0.001) decrease in serum Total Cholesterol (TC), Triglyceride (TG) and increase in High Density Lipoprotein (HDL) level as compared to normal group. Both the extracts have shown a non significant difference in the level of TG as compared to standard drug atorvastatin, depicting that the efficacy of extracts is at par with that of standard drug atorvastatin. Conclusion: Pharmacognostical study of the plant can be a very good tool for identification as well as authentication of a herb. Moreover, these parameters may be helpful in the development of monograph of the plant. Pharmacological activity confirmed Fagopyrum esculentum Moench. seed to be a good antioxidant and have lipid lowering potential.


Sign in / Sign up

Export Citation Format

Share Document