scholarly journals Effect of Recrystallization Technique on Oral Bioavailability of Valsartan

2021 ◽  
Vol 11 (6) ◽  
pp. 88-93
Author(s):  
TP Rao ◽  
N. Nalluri
Keyword(s):  
Oral Bioavailability ◽  
Wistar Rats ◽  
Relative Bioavailability ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Type I ◽  
Dissolution Properties ◽  
Male Wistar Rats

Valsartan (VAL) is a widely prescribed anti-hypertensive agent with angiotensin II type I receptor antagonistic activity. VAL belongs to BCS class II having a low and variable oral bioavailability (10-35%) and its absorption is dissolution rate limited. Recrystallization of VAL from different organic solvents improved VAL aqueous solubility and thereby in vitro dissolution properties. In this investigation in vivo oral bioavailability (BA) of VAL and its recrystallized products with methanol and ethanol (VMET and VETH respectively) solvents was evaluated in male Wistar rats. Also, a rapid, economical and reliable RP-HPLC-PDA method was developed for the estimation of VAL in rat plasma samples and validated according to ICH guidelines. Chromatographic separation was achieved on an Agilent eclipse C18 column (150×4.6mm, 5µ) with a mobile phase composition of 10mM ammonium acetate: acetonitrile (75:25%v/v) at a flow rate of 1.2 mL/min. The retention time of VAL was found to be 2.9 min and showed good linearity (R2>0.996) in the selected concentration range of 0.5-25µg/mL. A 2.9, 2.8 folds increase in Cmax and a relative bioavailability of 320, 305% was observed with VMET and VETH respectively, when compared to that of untreated VAL. Thus it can be inferred that recrystallization is easy and economical technique for enhancing the pharmaceutical properties like solubility, dissolution properties and oral BA of poorly water soluble drugs like VAL. Keywords: Bioanalytical method, Bioavailability, Male Wistar rats, Valsartan, Recrystallization

scholarly journals Development of a self-microemulsifying drug delivery system of domperidone: In vitro and in vivo characterization

2013 ◽  
Vol 63 (2) ◽  
pp. 241-251 ◽  
Author(s):  
Ramesh Jakki ◽  
Muzammil Afzal Syed ◽  
Prabhakar Kandadi ◽  
Kishan Veerabrahma
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Oral Bioavailability ◽  
Ternary Phase Diagram ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Size Analysis

The main objective of this work was to prepare a self-micro emulsifying drug delivery system (SMEDDS) for enhancement of oral bioavailability of domperidone, a poorly water soluble drug. The solubility of the drug was determined in various vehicles. A pseudo ternary phase diagram was constructed to identify the self-micro emulsification region. The in vitro self-micro emulsification properties and droplet size analysis of SMEDDS were studied following their addition to water under mild agitation. Further, the resultant formulations were investigated for clarity, phase separation, globule size, effect of pH and dilutions (1:100, 1:500, 1:1000) and freeze-thaw stability. The optimized formulation, SMEDDS-B used for in vitro dissolution and bioavailability assessment, contained oil (Labrafac CC, 25 %, m/m), surfactant (Tween 80, 55 %, m/m), and co-surfactant (Transcutol®, 20 %, m/m). The preliminary oral bioavailability of domperidone from SMEDDS was 1.92-fold higher compared to that of domperidone suspension in rats. The AUC0-24 and cmax values were 3.38 ± 0.81 μg h mL-1 and 0.44 ± 0.03 μg mL-1 for SMEDDS-B formulation in comparison with 1.74 ± 0.18 μg h mL-1 and 0.24 ± 0.02 μg mL-1 for domperidone suspension, suggesting a significant increase (p < 0.05) in oral bioavailability of domperidone from SMEDDSS.

Optimization of Nanostructured Lipid Carriers of Fenofibrate Using a Box-Behnken Design for Oral Bioavailability Enhancement

2021 ◽  
Vol 18 ◽  
Author(s):  
Huijuan Wang ◽  
Wei Hong ◽  
Xiangyu Li ◽  
Qian Jin ◽  
Weifeng Yea ◽  
...  
Keyword(s):  
Particle Size ◽  
Oral Bioavailability ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Nanostructured Lipid Carrier ◽  
Bioavailability Enhancement ◽  
Box Behnken Design ◽  
Predicted Values

Background: Fenofibrate (FNB) is a commonly used hypolipidemic agent. However, the oral bioavailability of FNB is limited by slow dissolution due to its low solubility. Thus, investigations on novel FNB formulations are necessary for their use. Objective: To enhance the oral bioavailability of FNB using optimized Nanostructured Lipid Carrier (NLC) formulations. Methods: Hot homogenization followed by ultrasonication was used to prepare FNB-NLCs. These formulations were optimized using a Box-Behnken design, where the amount of FNB (X1), a ratio of solid lipid/liquid lipid (X2), and the percentage of emulsifier (X3), were set as independent variables, while the particle size (Y1), and Entrapment Efficiency (EE%) (Y2), were used as dependent factors. An in vitro dissolution test was then performed using a paddle method, while an in vivo pharmacokinetic study of FNB-NLC formulation was performed in rats. Results: FNB-NLCs were successfully prepared and optimized using a Box-Behnken design. The particle size and EE% of the FNB-NLC had less than 5% difference from predicted values. The in vitro dissolution and oral bioavailability of the FNB-NLC were both higher than those of raw FNB. Results: FNB-NLCs were successfully prepared and optimized using a Box-Behnken design. The particle size and EE% of the FNB-NLC had less than 5% difference from predicted values. The in vitro dissolution and oral bioavailability of the FNB-NLC were both higher than those of raw FNB. Conclusion: A Box-Behnken design was successfully applied to optimize FNB-NLC formulation for the enhancement of the dissolution and bioavailability of FNB, a poorly water-soluble drug.

Fenofibrate Solid Dispersion for Improving Oral Bioavailability: Preparation, and Characterization and in vivo Evaluation

2020 ◽  
Vol 13 (5) ◽  
pp. 5102-5109
Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi
Keyword(s):  
Oral Bioavailability ◽  
Oral Delivery ◽  
Solid Dispersions ◽  
In Vitro Release ◽  
Aqueous Solubility ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
In Vivo Evaluation

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.

Optimization of Performance Variables of Exemestane Nanosuspension Using Box-Behnken Design to Improve Dissolution and Oral Bioavailability

2021 ◽  
Vol 18 ◽  
Author(s):  
Komal Parmar ◽  
Jay Shah
Keyword(s):  
Oral Bioavailability ◽  
In Vitro Dissolution ◽  
Pharmacokinetic Parameters ◽  
Average Particle ◽  
Stability Studies ◽  
Box Behnken Design ◽  
Media Milling ◽  
Dissolution Properties ◽  
Accelerated Stability

Purpose: Present investigation was aimed to fabricate nanocrystal of exemestane, an anticancer drug with poor dissolution properties and oral bioavailability. Methods: Influence of various process parameters on the formulation of exemestane nanosuspension using media milling technique were investigated in the trial batches. Box-Behnken design was applied with independent variables identified in the preliminary studies, viz. X1-Milling time, X2-Amount of stabilizer and X3-Amount of milling agent. In vitro dissolution and in vivo studies were carried out. Solid state characterization (PXRD, SEM, and DSC) studies demonstrated physical changes in drug due to nano-crystallization. Accelerated stability studies of optimized formulation were carried out. Results: Individual process attributes exhibited significant effect on the average particle size of exemestane nanosuspension. Dissolution studies revealed enhancement in drug release rate as compared to pure exemestane powder. The in vivo pharmacokinetic parameters of exemestane nanosuspension showed significant improvement in Cmax and AUC0-t, about 283.85% and 271.63% respectively suggesting amelioration in oral bioavailability by 2.7-fold as compared to pure exemestane. Accelerated stability studies of the optimized formulation suggested stability of the nanocrystals for at least sixmonth period. Conclusion: Nanocrystals prepared by media milling technique were successful in improving the poor dissolution properties and oral bioavailability of exemestane.

In Vitro and In Vivo Evaluation of Olmesartan Medoxomil Microcrystals and Nanocrystals: Preparation, Characterization, and Pharmacokinetic Comparison in Beagle Dogs

2019 ◽  
Vol 16 (6) ◽  
pp. 500-510
Author(s):  
Rong Chai ◽  
Hailing Gao ◽  
Zhihui Ma ◽  
Meng Guo ◽  
Qiang Fu ◽  
...  
Keyword(s):  
Particle Size ◽  
Oral Bioavailability ◽  
Olmesartan Medoxomil ◽  
Water Soluble ◽  
Size Reduction ◽  
Drug Dissolution ◽  
Beagle Dogs ◽  
Enhanced Solubility

Background: Olmesartan medoxomil (OLM) is a promising prodrug hydrolyzed to olmesartan (OL) during absorption from the gastrointestinal tract. OL is a selective angiotensin II receptor antagonist, with high drug resistance and low drug interaction. However, OLM has low solubility and low bioavailability. Therefore, it is extremely urgent to reduce the drug particle size to improve its biological bioavailability. Objective: The aim of the study was to improve the oral bioavailability of poorly water-soluble olmesartan medoxomil (OLM) by using different particle size-reduction strategies. Method: Raw drug material was micronized or nanosized by either jet or wet milling processes, respectively. The particle sizes of the prepared nanocrystals (100-300 nm) and microcrystals (0.5-16 μm) were characterized by DLS, SEM, and TEM techniques. Solid state characterization by XPRD and DSC was used to confirm the crystalline state of OLM after the milling processes. Results: We demonstrated that OLM nanocrystals enhanced solubility and dissolution in the non-sink condition in which high sensitivity was found in purified water. After 1 h, 65.4% of OLM was dissolved from nanocrystals, while microcrystals and OLMETEC® only showed 37.8% and 31.9% of drug dissolution, respectively. In the pharmacokinetic study using Beagle dogs, an increase in Cmax (～2 fold) and AUC (～1.6 fold) was observed after oral administration of OLM nanocrystals when compared to microcrystals and reference tablets, OLMETEC®. In contrast, OLM microcrystals failed to improve the oral bioavailability of the drugs. Conclusion: Particles size reduction to nano-scale by means of nanocrystals technology significantly increased in vitro dissolution rate and in vivo oral bioavailability of OLM.

Concomitant release of sialic acids and calcium by neuraminidase from rat aorta in situ

1988 ◽  
Vol 235 (1279) ◽  
pp. 139-144 ◽  
Keyword(s):  
Sialic Acid ◽  
Wistar Rats ◽  
Rat Aorta ◽  
Sialic Acids ◽  
Molar Ratio ◽  
Male Wistar Rats

Male Wistar rats were heparinized and killed with pentobarbital. The upper and lower ends of the aortae were cannulated and the blood was washed out with saline until the washings contained calcium and sialic-acid-reacting material at minimal concentrations. The aortae were perfused with neuraminidase for 15 min. This caused the appearance of calcium as well as of sialic acids in the perfusate in total amounts of about 5.3 nmol and about 3.6 nmol per aorta respectively. The molar ratio of about 1.5 is sufficiently close to that determined for the association of calcium with sialic acids in vitro to suggest that their association is similar in vivo .

scholarly journals Synthesis of Some Novel Derivatives of 2-(9H-purin-6-ylsulfanyl) Acetohydrazide as Potential Antithyroid Agents

2017 ◽  
Vol 56 (4) ◽  
Author(s):  
Ismat Fatima ◽  
Munawar A. Munawar ◽  
Waqar Nasir ◽  
Misbahul A. Khan ◽  
Affia Tasneem ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Male Wistar Rats ◽  
Antithyroid Agents ◽  
Derivatives Of

Some novel derivatives of 2-(9<em>H</em>-Purin-6-ylsulfanyl)acetohydrazide were synthesized by reacting it with respective aldehydes in ethanol. The antithyroid effect of these compounds was ascertained <em>in vitro</em> by studying their complexation with iodine spectrophotometrically. <em>In vivo</em>, the hormonal as well as histological variations in male Wistar rats demonstrated significant antithyroid potential (p ≤ 0.05) of these compounds.

scholarly journals ENHANCEMENT OF SOLUBILITY AND BIOAVAILABILITY OF BCS CLASS-II AMBRISENTAN: IN VITRO, IN VIVO AND EX VIVO ANALYSIS

2022 ◽  
pp. 67-74
Author(s):  
RAHUL RADKE ◽  
NEETESH K. JAIN
Keyword(s):  
Solid Dispersion ◽  
Ex Vivo ◽  
Class Ii ◽  
Water Soluble ◽  
Pure Form ◽  
In Vitro Dissolution ◽  
Drug Solubility ◽  
Bcs Class Ii

Objective: The aim of this investigation was to enhance the solubility and bioavailability of the BCS class II poorly water-soluble drug ambrisentan by solid dispersion (SD) techniques using Gelucire 50/13 as a hydrophilic carrier. Methods: Solid dispersion of ambrisentan was prepared by kneading method using different dug: carrier ratios. Prepared SD was characterized for solubility, drug content, percentage yield, in vitro dissolution, ex vivo permeation and bioavailability. Solid-state characterization was performed by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results: All the SDs formulations showed increase in drug solubility and dissolution when compared with its pure form. Aqueous solubility of the drug was found to be increased 8.23 fold in SD. DSC study showed that endothermic peak of the drug was disappeared in spectra of SD, confirming its amorphous conversion, XRD study revealed the reduction to almost absence of specific high-intensity peaks of drug which confirmed the reduction of crysatallinity of ambrisentan in SD. SEM of optimized SD formulation demonstrates the complete encapsulation and solubilization drug. In vitro dissolution study showed that optimized SD formulation (ASD4) gives the faster drug release of 101.5% in 60 min, as compare to its pure form and other SD formulations. Conclusion: Solid dispersion ASD4 prepared with 1:4 drug to carrier ratio showed the highest drug solubility and in vitro dissolution. The ex vivo and in vivo studies performed on optimized formulation ASD4 showed enhancement in drug permeability and bioavailability in Gelucire 50/13 based SD formulation.

Sign in / Sign up

Export Citation Format

Share Document