Evaluation of a Convective Diffusion Drug Dissolution Rate Model

1975 ◽  
Vol 64 (9) ◽  
pp. 1518-1520 ◽  
Author(s):  
Kenneth G. Nelson ◽  
Ashok C. Shah
Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 344
Author(s):  
Jong-Hwa Lee ◽  
Hyeong Sik Jeong ◽  
Jong-Woo Jeong ◽  
Tae-Sung Koo ◽  
Do-Kyun Kim ◽  
...  

Rivaroxaban (RXB), a novel oral anticoagulant that directly inhibits factor Xa, is a poorly soluble drug belonging to Biopharmaceutics Classification System (BCS) class II. In this study, a hot-melt extruded amorphous solid dispersion (HME-ASD) containing RXB is prepared by changing the drug:polymer ratio (Polyvinylpyrrolidione-vinyl acetate 64, 1:1–1:4) and barrel temperature (200–240 °C), fixed at 20% of Cremophor® RH 40 and 15 rpm of the screw speed, using the hot-melt extruding technique. This study evaluates the solubility, dissolution behavior, and bioavailability for application to oral drug delivery and optimizes the formulation of rivaroxaban amorphous solid dispersion (RXB-ASD). Based on a central composite design, optimized RXB-ASD (PVP VA 64 ratio 1:4.1, barrel temperature 216.1 °C, Cremophor® RH 40 20%, screw speed 15 rpm) showed satisfactory results for dependent variables. An in vitro drug dissolution study exhibited relatively high dissolution in four media and achieved around an 80% cumulative drug release in 120 min. Optimized RXB-ASD was stable under the accelerated condition for three months without a change in crystallinity and the dissolution rate. A pharmacokinetic study of RXB-ASD in rats showed that the absorption was markedly increased in terms of rate and amount, i.e., the systemic exposure values, compared to raw RXB powder. These results showed the application of quality by design (QbD) in the formulation development of hot-melt extruded RXB-ASD, which can be used as an oral drug delivery system by increasing the dissolution rate and bioavailability.


2018 ◽  
Vol 8 (5-s) ◽  
pp. 293-300 ◽  
Author(s):  
Rajesh Shankar Jagtap ◽  
Rajendra Doijad ◽  
Shrinivas Mohite

The enhancement in solubility and dissolution rate of BCS class-II drug Nifedipine was achieved by simple physical mixture with sepitrap 80 & sepitrap 4000 in 1:1 & 1:2 proportion. The saturation solubility studies shows 263 % & 368 % increase in the solubility in physical mixture of Nifedipine with sepitrap 80 & sepitrap 4000 respectively. The physicochemical properties of pure Nifedipine compared to their physical mixtures with sepitrap 80 & sepitrap 4000 were determined using FTIR, DSC & PXRD. The FTIR and DSC studies shows no any interaction in Nifedipine and sepitrap, the marked broadening and distinct reduction in intensity with shifting of drug endotherm was displayed physical mixture with sepitrap demonstrate positive effect. The PXRD diffractograms shows distinctive peaks but reduction in peak intensity in terms of counts indicating conversion of drug in amorphous forms. The surface morphology of the prepared physical mixture was examined by SEM which indicating no significant change in its surface morphology due to no use any solvent during the preparation of physical mixture . Photostability studies shows that rate of photo degradation is very slow in Physical mixture with sepitrap as compared to pure Nifedipine. Dissolution studies in SGF & SIF shows that significant enhancement by use of novel solubilizer sepitrap 80 as well as sepitrap 4000 in 1:2 proportions. The physical mixture containing sepitrap 4000 was found stable as there was no any significant change in appearance and drug dissolution after three month stability studies.


2011 ◽  
Vol 393-395 ◽  
pp. 119-122
Author(s):  
Dong Hua Wan ◽  
Fen Lin ◽  
Qu Xiang Liao

It’s well known that curcumin is practically insoluble in water. Therefore, to improve the drug dissolution rate, fusion approach was employed to prepare curcumin solid dispersions (SDs) in the carrier Pluronic F68 with three different drug loads. The dissolution rate of curcumin from the SDs was measured at simulated gastric fluid. The concentration of the dissolved drug in the medium was determined by HPLC. The dissolution rates of the formulations were dependent on the drug loading in SDs. 92.2% CUR was dissolved in 10 min from the SDs with 8.97% drug load, whereas the amounts of drug released were 65.8% and 84.2% within 120 min from the SDs with 18.9% and 29.0% drug loads, respectively. The Fourier transform infrared spectra indicated hydrogen bond between the drug and carrier. Furthermore, their physicochemical properties were well investigated using differential scanning calorimetry and X-ray diffraction. In the dispersions containing 8.97% CUR, the drug was in the molecular state. At a composition of approximately 18.9%, CUR was dispersed as micro-fine crystals. These interesting results indicate that the physical states of the drug in the carrier, which are governed by the drug loading, can affect the dissolution rate improvement.


2009 ◽  
Vol 14 (4) ◽  
pp. 400-408 ◽  
Author(s):  
Erik Kaunisto ◽  
Bernt Nilsson ◽  
Anders Axelsson

INDIAN DRUGS ◽  
2021 ◽  
Vol 57 (11) ◽  
pp. 22-26
Author(s):  
Manisha Dhere ◽  
◽  
Arti Majumdar ◽  
Neelesh Malviya

In the present research, newly developed complex with sodium caprylate was investigated for solubility and dissolution enhancement of eluxadoline. Complexes were prepared in different ratios by solvent evaporation method and characterised solubility study, Infrared spectroscopy (IR), Diffrential scanning calorimetry (DSC), X-Ray Diffraction (XRD), drug content analysis and in vitro Drug release. The solubility and dissolution rate revealed most suitable ratio of eluxadoline and sodium caprylate (1:4). The IR, DSC and X-RD data also confirmed the results. It was concluded that complex prepared with (1:4 drug:sodium caprylate ratio) using solvent evaporation method showed significant improvement in solubility and drug dissolution.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 393 ◽  
Author(s):  
Jannes van der Merwe ◽  
Jan Steenekamp ◽  
Dewald Steyn ◽  
Josias Hamman

Many active pharmaceutical ingredients (APIs) exhibit poor solubility and low dissolution rates in aqueous environments such as the luminal fluids of the gastrointestinal tract. The oral bioavailability of these compounds is usually very low as a result of their poor solubility properties. In order to improve the bioavailability of these poorly soluble drugs, formulation strategies have been applied as a means to improve their aqueous solubility and dissolution rates. With respect to formulation approaches, excipients can be incorporated in the formulation to assist in the dissolution process of the drug, or specialized dosage forms can be formulated that improve dissolution rate through various mechanisms. This paper provides an overview of selected excipients (e.g., alkalinizing agents, surfactants and sugars) that can be used in formulations to increase the dissolution rate as well as specialized dosage forms such as self-emulsifying delivery systems and formulation techniques such as inclusion complexes and solid dispersions. These formulation approaches are discussed with available examples with specific reference to positive outcomes in terms of drug solubility and bioavailability enhancement.


2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Xin Yang ◽  
Xinrong Liu ◽  
Wanjun Zang ◽  
Zhiyong Lin ◽  
Qiyun Wang

By calculating the concentration distributions of rock salt solutions at the boundary layer, an ordinary differential equation for describing a special dissolution rate model of rock salt under the assumption of an instantaneous diffusion process was established to investigate the dissolution mechanism of rock salt under transient but stable conditions. The ordinary differential equation was then solved mathematically to give an analytical solution and related expressions for the dissolved radius and solution concentration. Thereafter, the analytical solution was fitted with transient dissolution test data of rock salt to provide the dissolution parameters at different flow rates, and the physical meaning of the analytical formula was also discussed. Finally, the influential factors of the analytical formula were investigated. There was approximately a linear relationship between the dissolution parameters and the flow rate. The effects of the dissolution area and initial volume of the solution on the dissolution rate equation of rock salt were computationally investigated. The results showed that the present analytical solution gives a good description of the dissolution mechanism of rock salt under some special conditions, which may provide a primary theoretical basis and an analytical way to investigate the dissolution characteristics of rock salt.


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