Noninvasive Monitoring of Local Drug Release Using X-ray Ccomputed Tomography: Optimization and In Vitro/In Vivo Validation

2003 ◽  
Vol 92 (2) ◽  
pp. 289-296 ◽  
Author(s):  
Agata Szymanski-Exner ◽  
Nicholas T. Stowe ◽  
Kyle Salem ◽  
Roee Lazebnik ◽  
John R. Haaga ◽  
...  
Keyword(s):  
Drug Release ◽  
Noninvasive Monitoring ◽  
X Ray ◽  
In Vivo Validation

Modeling diffusion-based drug release inside a nerve conduit in vitro and in vivo validation study

2020 ◽  
Author(s):  
Pratima Labroo ◽  
Scott Ho ◽  
Himanshu Sant ◽  
Jill E. Shea ◽  
Jayant Agarwal ◽  
...  
Keyword(s):  
Drug Release ◽  
Validation Study ◽  
Nerve Conduit ◽  
In Vivo Validation

Preparation of cultured astrocytes for x-ray microanalysis

1989 ◽  
Vol 47 ◽  
pp. 988-989
Author(s):  
N.K.R. Smith ◽  
K.E. Hunter ◽  
P. Mobley ◽  
L.P. Felpel
Keyword(s):  
Cultured Cells ◽  
Elemental Content ◽  
Elemental Distribution ◽  
Sprague Dawley ◽  
X Ray ◽  
Cultured Astrocytes ◽  
Freeze Dried ◽  
Ultimate Objective

Electron probe energy dispersive x-ray microanalysis (XRMA) offers a powerful tool for the determination of intracellular elemental content of biological tissue. However, preparation of the tissue specimen , particularly excitable central nervous system (CNS) tissue , for XRMA is rather difficult, as dissection of a sample from the intact organism frequently results in artefacts in elemental distribution. To circumvent the problems inherent in the in vivo preparation, we turned to an in vitro preparation of astrocytes grown in tissue culture. However, preparations of in vitro samples offer a new and unique set of problems. Generally, cultured cells, growing in monolayer, must be harvested by either mechanical or enzymatic procedures, resulting in variable degrees of damage to the cells and compromised intracel1ular elemental distribution. The ultimate objective is to process and analyze unperturbed cells. With the objective of sparing others from some of the same efforts, we are reporting the considerable difficulties we have encountered in attempting to prepare astrocytes for XRMA.Tissue cultures of astrocytes from newborn C57 mice or Sprague Dawley rats were prepared and cultured by standard techniques, usually in T25 flasks, except as noted differently on Cytodex beads or on gelatin. After different preparative procedures, all samples were frozen on brass pins in liquid propane, stored in liquid nitrogen, cryosectioned (0.1 μm), freeze dried, and microanalyzed as previously reported.

Preparation and Evaluation of Gemifloxacin Mesylate Floating Matrix Tablets in Healthy Human Volunteers

2017 ◽  
Vol 10 (1) ◽  
pp. 3623-3630
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Haarika B ◽  
Jyothi Sri S ◽  
K Abbulu
Keyword(s):  
Drug Release ◽  
Sodium Bicarbonate ◽  
Polymer Concentration ◽  
Hydroxypropyl Methylcellulose ◽  
Matrix Tablets ◽  
Physical Parameters ◽  
Drug Bioavailability ◽  
Floating Tablets

The purpose of present investigation was to develop floating matrix tablets of gemifloxacin mesylate, which after oral administration could prolong the gastric residence time, increase the drug bioavailability and diminish the side effects of irritating drugs. Tablets containing drug, various viscosity grades of hydroxypropyl methylcellulose such as HPMC K4M and HPMC K15M as matrix forming agent, Sodium bicarbonate as gas-forming agent and different additives were tested for their usefulness in formulating gastric floating tablets by direct compression method. The physical parameters, in vitro buoyancy, release characteristics and in vivo radiographic study were investigated in this study. The gemifloxacin mesylate floating tablets were prepared using HPMC K4M polymer giving more sustained drug release than the tablet containing HPMC K15M. All these formulations showed floating lag time of 30 to 47 sec and total floating time more than 12 h. The drug release was decreased when polymer concentration increases and gas generating agent decreases. Formulation that contains maximum concen-tration of both HPMC K15M and sodium bicarbonate (F9) showing sufficiently sustained with 99.2% of drug release at 12 h. The drug release from optimized formulation follows Higuchi model that indicates the diffusion controlled release. The best formulation (F9) was selected based on in vitro characteristics and used in vivo radiographic studies by incorporating barium sulphate as a radio-opaque agent and the tablet remained in the stomach for about 6 h.   

Design and In vivo Evaluation of Palonosetron HCl Mouth Dissolving Films in the Management of Chemotherapy-Induced Vomiting

2017 ◽  
Vol 10 (6) ◽  
pp. 3929-3936
Author(s):  
Y. Srinivasa Rao ◽  
K. Adinarayana Reddy
Keyword(s):  
Drug Release ◽  
Patient Compliance ◽  
Onset Of Action ◽  
In Vivo Evaluation ◽  
Disintegration Time ◽  
In Vitro Drug Release ◽  
Surface Ph ◽  
Drug Content

Fast dissolving oral delivery systems are solid dosage forms, which disintegrate or dissolve within 1 minute in the mouth without drinking water or chewing. Mouth dissolving film (MDF) is a better alternate to oral disintegrating tablets due to its novelty, ease of use and the consequent patient compliance. The purpose of this work was to develop mouth dissolving oral films of palonosetron HCl, an antiemetic drug especially used in the prevention and treatment of chemotherapy-induced nausea and vomiting. In the present work, the films were prepared by using solvent casting method with various polymers HPMC E3, E5 & E15 as a film base synthetic polymer, propylene glycol as a plasticizer and maltodextrin and other polymers. Films were found to be satisfactory when evaluated for thickness, in vitro drug release, folding endurance, drug content and disintegration time. The surface pH of all the films was found to be neutral. The in vitro drug release of optimized formulation F29 was found to be 99.55 ± 6.3 7% in 7 min. The optimized formulation F29 also showed satisfactory surface pH, drug content (99.38 ± 0.08 %), disintegration time of 8 seconds and good stability. FTIR data revealed that no interaction takes place between the drug and polymers used in the optimized formulation. In vitro and in vivo evaluation of the films confirmed their potential as an innovative dosage form to improve delivery and quick onset of action of Palonosetron Hydrochloride. Therefore, the mouth dissolving film of palonosetron is potentially useful for the treatment of emesis disease where quick onset of action is desired, also improved patient compliance.

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.  

Gastroretentive Floating Capsules of Risedronate Sodium: Development, Optimization, in vitro and in vivo Evaluation in Healthy Human Volunteers

2015 ◽  
Vol 8 (2) ◽  
pp. 2835-2842
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Arun Kumar Jarathi ◽  
Suresh Gande ◽  
Viswaja Medipally ◽  
Ramesh Bomma
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Zero Order ◽  
Wet Granulation ◽  
Capsule Formulation ◽  
In Vivo Evaluation ◽  
Healthy Human ◽  
X Ray ◽  
Human Volunteers

Background and the purpose of the study: Risedronate sodium inhibits osteoclast bone resorption and modulates bone metabolism. Risedronate has a high affinity for hydroxyapatite crystals in bone and is a potent antiresorptive agent. In the present investigation efforts were made to improve the bioavailability of risedronate sodium by increasing the residence time of the drug through sustained-release matrix capsule formulation via gastroretentive mechanism. Capsules were prepared by wet granulation technique. The influence of gel forming agents, amount of risedronate and total weight of capsules on physical properties, in vitro buoyancy, drug release, FTIR, DSC, X-ray studies were investigated. The release mechanisms were explored and explained by applying zero order, first order, Higuchi and Korsmeyer equations. The selected formulations were subjected to stability study at 40 °C/75% RH, 25 °C/60% RH for the period of three months. For all formulations, kinetics of drug release from capsules followed Higuchi’s square root of time kinetic treatment heralding diffusion as predominant mechanism of drug release. Formulation containing 25 mg HPMC K4M and 75 mg HPMC K100 LV (F-8) showed zero order release profile. There was no significant change in the selected formulation, when subjected to accelerated stability conditions over a period of three months. X-ray imaging in six healthy human volunteers revealed a mean gastric retention period of 5.60 ± 0.77 hrs for the selected formulation. Stable, sustained release effervescent floating capsules of risedronate sodium could be prepared by wet granulation technique.  

Synthesis, Characterization and in vivo Evaluation of PEGylated PPI Dendrimer for Safe and Prolonged Delivery of Insulin

2019 ◽  
Vol 9 (3) ◽  
pp. 248-263 ◽  
Author(s):  
Ashish K. Parashar ◽  
Preeti Patel ◽  
Arun K. Gupta ◽  
Neetesh K. Jain ◽  
Balak Das Kurmi
Keyword(s):  
Blood Glucose ◽  
Drug Release ◽  
Blood Glucose Level ◽  
Glucose Level ◽  
Albino Rats ◽  
Sustained Delivery ◽  
In Vivo Evaluation ◽  
Hemolytic Toxicity

Background: The present study was aimed at developing and exploring the use of PEGylated Poly (propyleneimine) dendrimers for the delivery of an anti-diabetic drug, insulin. Methods: For this study, 4.0G PPI dendrimer was synthesized by successive Michael addition and exhaustive amidation reactions, using ethylenediamine as the core and acrylonitrile as the propagating agent. Two different activated PEG moieties were employed for PEGylation of PPI dendrimers. Various physicochemical and physiological parameters UV, IR, NMR, TEM, DSC, drug entrapment, drug release, hemolytic toxicity and blood glucose level studies of both PEGylated and non- PEGylated dendritic systems were determined and compared. Results: PEGylation of PPI dendrimers caused increased solubilization of insulin in the dendritic framework as well as in PEG layers, reduced drug release and hemolytic toxicity as well as increased therapeutic efficacy with reduced side effects of insulin. These systems were found to be suitable for sustained delivery of insulin by in vitro and blood glucose-level studies in albino rats, without producing any significant hematological disturbances. Conclusion: Thus, surface modification of PPI dendrimers with PEG molecules has been found to be a suitable approach to utilize it as a safe and effective nano-carrier for drug delivery.

scholarly journals Development and In Vitro-In Vivo Evaluation of a Novel Sustained-Release Loxoprofen Pellet with Double Coating Layer

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 260 ◽  
Author(s):  
Dongwei Wan ◽  
Min Zhao ◽  
Jingjing Zhang ◽  
Libiao Luan
Keyword(s):  
Citric Acid ◽  
Drug Release ◽  
Sustained Release ◽  
Release Rate ◽  
Diffusion Rate ◽  
Immediate Release ◽  
Pharmacokinetic Studies ◽  
Release Tablet

This study aimed to develop a novel sustained release pellet of loxoprofen sodium (LXP) by coating a dissolution-rate controlling sub-layer containing hydroxypropyl methyl cellulose (HPMC) and citric acid, and a second diffusion-rate controlling layer containing aqueous dispersion of ethyl cellulose (ADEC) on the surface of a LXP conventional pellet, and to compare its performance in vivo with an immediate release tablet (Loxinon®). A three-level, three-factor Box-Behnken design and the response surface model (RSM) were used to investigate and optimize the effects of the citric acid content in the sub-layer, the sub-layer coating level, and the outer ADEC coating level on the in vitro release profiles of LXP sustained release pellets. The pharmacokinetic studies of the optimal sustained release pellets were performed in fasted beagle dogs using an immediate release tablet as a reference. The results illustrated that both the citric acid (CA) and ADEC as the dissolution- and diffusion-rate controlling materials significantly decreased the drug release rate. The optimal formulation showed a pH-independent drug release in media at pH above 4.5 and a slightly slow release in acid medium. The pharmacokinetic studies revealed that a more stable and prolonged plasma drug concentration profile of the optimal pellets was achieved, with a relative bioavaibility of 87.16% compared with the conventional tablets. This article provided a novel concept of two-step control of the release rate of LXP, which showed a sustained release both in vitro and in vivo.

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