Evaluating HIFU‐mediated local drug release using thermal strain imaging: Phantom and preliminary in‐vivo studies

2019 ◽  
Vol 46 (9) ◽  
pp. 3864-3876 ◽  
Author(s):  
Fu‐Feng Lee ◽  
Qiong He ◽  
Jing Gao ◽  
Anni Pan ◽  
Suhui Sun ◽  
...  
Keyword(s):  
Drug Release ◽  
Thermal Strain ◽  
Strain Imaging ◽  
In Vivo Studies ◽  
Thermal Strain Imaging

Thermal strain imaging in vivo using interpolated IQ-images

Ultrasonics ◽  
2021 ◽  
Vol 110 ◽  
pp. 106292
Author(s):  
Chuhao Yin ◽  
Guanzhu Wang ◽  
Kexin Yang ◽  
Juan Tu ◽  
Xiasheng Guo ◽  
...  
Keyword(s):  
Thermal Strain ◽  
Strain Imaging ◽  
Thermal Strain Imaging

Formulation and In Vivo Evaluation of Mucoadhesive Micro-spheres of Rebamipide, a Mucoprotective Drug for GIT Disorders

2018 ◽  
Vol 11 (3) ◽  
pp. 4089-4097
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Kanteepan P
Keyword(s):  
Drug Release ◽  
Entrapment Efficiency ◽  
In Vivo Studies ◽  
Amino Acid Derivative ◽  
Release Mechanism ◽  
In Vivo Evaluation ◽  
In Vitro Drug Release ◽  
Percentage Yield

Rebamipide, an amino acid derivative of 2-(1H)-quinolinone, is used for mucosal protection, healing of gastroduodenal ulcers, and treatment of gastritis. The current research study aimed to develop novel gastro-retentive mucoadhesive microspheres of rebamipide using ionotropic gelation technique. Studies of micromeritic properties confirmed that microspheres were free flowing with good packability. The in vitro drug release showed the sustained release of rebamipide up to 99.23 ± 0.13% within 12 h whereas marketed product displayed the drug release of 95.15 ± 0.23% within 1 h. The release mechanism from microspheres followed the zero-order and Korsmeyer-Peppas (R2 = 0.915, 0.969), respectively. The optimized M12 formulation displayed optimum features, such as entrapment efficiency 97%, particle size 61.94 ± 0.11 µm, percentage yield 98%, swelling index 95% and mucoadhesiveness was 97%. FTIR studies revealed no major incompatibility between drug and excipients. SEM confirmed the particles were of spherical in shape. Optimized formulation (M12) were stable at 40°C ± 2°C/75% RH ± 5% RH for 6 months. In vivo studies were performed and kinetic parameters like Cmax, Tmax, AUC0-t, AUC0-∞, t1/2, and Kel  were calculated. The marketed product Cmax (3.15 ± 0.05 ng/mL) was higher than optimized formulation (2.58 ± 0.03 ng/mL). The optimized formulation AUC0-t (15.25 ± 1.14 ng.hr/mL), AUC0-∞ (19.42 ± 1.24 ng.hr/mL) was significantly higher than that of marketed product AUC0-t (10.21 ± 1.26 ng.hr/mL) and AUC0-∞ (13.15 ± 0.05 ng.hr/mL). These results indicate an optimized formulation bioavailability of 2.5-fold greater than marketed product.  

Thermal Strain Imaging of Thermal Flying-Height-Controlled Magnetic Head

2009 ◽  
Vol 2 (12) ◽  
pp. 126504 ◽  
Author(s):  
Keiji Takata ◽  
Noriyasu Ichimei ◽  
Mitsuhiro Okuda
Keyword(s):  
Thermal Strain ◽  
Strain Imaging ◽  
Flying Height ◽  
Magnetic Head ◽  
Thermal Strain Imaging

scholarly journals DESIGN AND IN VITRO/IN VIVO EVALUATION OF EXTENDED RELEASE MATRIX TABLETS OF NATEGLINIDE

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Mohini Sihare ◽  
Rajendra Chouksey
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Release Profile ◽  
Matrix Tablets ◽  
In Vivo Studies ◽  
Release Mechanism ◽  
In Vivo Evaluation

Aim: Nateglinide is a quick acting anti-diabetic medication whose potent activity lasts for a short duration. One of the dangerous side effects of nateglinide administration is rapid hypoglycemia, a condition that needs to be monitored carefully to prevent unnecessary fatalities. The aim of the study was to develop a longer lasting and slower releasing formulation of nateglinide that could be administered just once daily. Methods: Matrix tablets of nateglinide were prepared in combination with the polymers hydroxypropylmethylcellulose (HPMC), eudragits, ethyl cellulose and polyethylene oxide and the formulated drug release patterns were evaluated using in vitro and in vivo studies. Conclusion: Of the seventeen formulated matrix tablets tested, only one formulation labelled HA-2 that contained 15% HPMC K4M demonstrated release profile we had aimed for. Further, swelling studies and scanning electron microscopic analysis confirmed the drug release mechanism of HA-2. The optimized formulation HA-2 was found to be stable at accelerated storage conditions for 3 months with respect to drug content and physical appearance. Mathematical analysis of the release kinetics of HA-2 indicated a coupling of diffusion and erosion mechanisms. In-vitro release studies and pharmacokinetic in vivo studies of HA-2 in rabbits confirmed the sustained drug release profile we had aimed for. Keywords: Hydroxypropylmethylcellulose, Matrix tablets, Nateglinide, Sustained release

scholarly journals Design and Characterization of Combinational Domperidone-Famotidine Floating Drug Delivery System - In vitro and In vivo studies

2021 ◽  
Vol 62 (2) ◽  
pp. 144-162
Author(s):  
Mounika Chidurala ◽  
Raveendra Reddy J
Keyword(s):  
Drug Release ◽  
Oral Administration ◽  
Quality By Design ◽  
Release Kinetics ◽  
Cost Effective ◽  
Fickian Diffusion ◽  
In Vivo Studies ◽  
Pharmacokinetic Studies

Introduction: The drawbacks assosiated with oral administration of drugscan be controlled or minimized by gastro retentive formulations that remain buoyant within the stomach for an extended time by providing prolonged gastric retention and releasethe drug in an exceedingly extended manner thereby improving bioavailability. The current research was to develop and optimize Domperidone and Famotidine floating tablets with extended release by Quality by Design approach. Method: Based on QTPP (Quality Target Product Profile), CQAs (Critical Quality Attributes)wereidentified. Risk analysis by the evaluation of formulation and process parameters showed that optimizing the levels of polymers could reduce high risk to achieve the target profile. A 23factor experimental design with midpoints was selected for statistical analysis and optimization. Results: HPMC K100 and Carbopol 934P had a positive effect while ethyl cellulose demonstrated a negative effect on the selected responses. Drug release kinetics followed the first-order release with Higuchi diffusion and Fickian diffusion. Optimized formula satisfying all the required parameters was selected and evaluated. The predicted response values were in close agreement with experimental response values. Abdominal X-ray imaging after oral administration of the tablets on a healthy rabbit’s stomach confirmed the extended floating behavior with shorter lag time. In vivo, pharmacokinetic studies in rabbits revealed that the optimized formulation exhibited prolonged drug release with enhanced Cmax, tmax, AUCo-t, and t1/2 of an optimized product when compared to the marketed product. Conclusions: It has been concluded that the application of Quality by Design in the formulation and optimization reduced the number of trials to produce a cost-effective formula.

Quality by Design enabled anti-hypertensive Floating drug delivery system by Risk assessment and Design of Experiment (DoE) – In vitro – In vivo correlation studies

2021 ◽  
Vol 16 ◽  
Author(s):  
Mounika Chidurala ◽  
Raveendra Reddy J
Keyword(s):  
Drug Release ◽  
Risk Analysis ◽  
Quality By Design ◽  
Release Kinetics ◽  
Cost Effective ◽  
Fickian Diffusion ◽  
In Vivo Studies ◽  
Pharmacokinetic Studies

Background: The present research aimed to develop and optimize extended-release floating tablets of Sacubitril and Valsartan through Quality by Design (QbD) approach. Risk analysis by formulation assessment and process parameters showed that optimizing the levels of the polymer will minimize high risk to meet the target profile. A two (2) level three (3) full factorial experimental design along with midpoints was carefully chosen for optimization and statistical analysis. Based on the literature, the independent and dependent variables were selected. Results: HPMC K100, Carbopol 934P had a positive effect, whereas Ethylcellulose had a negative effect on Floating time, drug release at 2 h, drug release at 12 h and, 50% responses. Drug release kinetics followed the first-order release with Higuchi and Fickian diffusion. Contour and overlay plots were utilized for an assortment of design space and optimized formula. ANOVA results of all the factors exhibited significance at p<0.05. Abdominal X-ray imaging of the optimized tablets on healthy rabbit’s stomach confirmed the floating behavior for more than 12 h. In vivo pharmacokinetic studies in rabbits showed that the optimized formulation exhibited prolonged and extended drug release with improved Cmax, tmax, AUCo-t, and t1/2 of test product when compared to marketed product. IVIVC model was developed by using dissolution data of in vitro and pharmacokinetics data of in-vivo by de-convolution method (Wagner-Nelson method). Conclusion: The Quality by Design implementation in the formulation and optimization abridged the number of trials to produce a cost-effective formula. In vivo studies confirmed that the formula was successfully developed with extended floating time (12 h) and drug release by risk analysis and experimental designs. Level A correlation was observed which confirmed a good correlation between in vitro and in vivo data.

scholarly journals Preparation and preclinical evaluation of aceclofenac loaded pectinate mucoadhesive microspheres

2012 ◽  
Vol 2 (1) ◽  
pp. 8 ◽  
Author(s):  
Santanu Chakraborty ◽  
Priyanka Nayak ◽  
Bala Murali Krishna ◽  
Madhusmruti Khandai ◽  
Ashoke Kumar Ghosh
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Polymer Concentration ◽  
Research Work ◽  
In Vivo Studies ◽  
Systemic Absorption ◽  
Cross Linking ◽  
Significant Difference

The aim of the present research work was to fabricate aceclofenac loaded pectinate microspheres by ionic gelation method and evaluate the effect of different cross-linking agents and polymer concentration on particle size, encapsulation efficacy and drug release behavior. It was also investigated that whether this pectinate dosage form was able to target the drug release in intestinal region and prevent the different side effect associated with the drug in stomach or not. It was observed that particle size, encapsulation efficacy and in vitro drug release were largely depended on polymer concentration and cross-linking agents. It was also observed that pectinate microspheres showed excellent pH depended mucoadhesive properties and they were able to restrict the drug release in stomach. <em>In vitro</em> drug release study showed that alminium-pectinate microspheres have more sustaining property as compared to barium-pectinate microspheres. Holm-Sidak multiple comparison analysis suggested a significant difference in measured t<sub>50%</sub> values among all the formulations with same cross-linking agent. In vivo studies revealed that the anti inflammatory and analgesic effects induced by pectinate microspheres were significantly high and prolonged as compared to pure drug. So, pectinate microspheres can be an excellent carrier for targeting the delivery of aceclofenac as well as help in improving the patient compliance by prolonging the systemic absorption.

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