scholarly journals Crystal-liquid Fugacity Ratio as a Surrogate Parameter for Intestinal Permeability

2016 ◽  
Vol 19 (3) ◽  
pp. 312 ◽  
Author(s):  
Parvin Zakeri-Milani ◽  
Zohreh Fasihi ◽  
Jafar Akbari ◽  
Ensieh Jannatabadi ◽  
Mohammad Barzegar-Jalali ◽  
...  

Background: We assessed the feasibility of using crystal-liquid fugacity ratio (CLFR) as an alternative parameter for intestinal permeability in the biopharmaceutical classification (BCS) of passively absorbed drugs. Methods: Dose number, fraction of dose absorbed, intestinal permeability, and intrinsic dissolution rate were used as the input parameters. CLFR was determined using thermodynamic parameters i.e., melting point, molar fusion enthalpy, and entropy of drug molecules obtained using differential scanning calorimetry. Results: The CLFR values were in the range of 0.06-41.76 mole percent. There was a close relationship between CLFR and in vivo intestinal permeability (r > 0.8). CLFR values of greater than 2 mole percent corresponded to complete intestinal absorption. Applying CLFR versus dose number or intrinsic dissolution rate, more than 92% of tested drugs were correctly classified with respect to the reported classification system on the basis of human intestinal permeability and solubility. Conclusion: This investigation revealed that the CLFR might be an appropriate parameter for quantitative biopharmaceutical classification. This could be attributed to the fact that CLFR could be a measure of solubility of compounds in lipid bilayer which was found in this study to be directly proportional to the intestinal permeability of compounds. This classification enables researchers to define characteristics for intestinal absorption of all four BCS drug classes using suitable cutoff points for both intrinsic dissolution rate and crystal-liquid fugacity ratio. Therefore, it may be used as a surrogate for permeability studies. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 289
Author(s):  
Debora Zanolla ◽  
Dritan Hasa ◽  
Mihails Arhangelskis ◽  
Gabriela Schneider-Rauber ◽  
Michele R. Chierotti ◽  
...  

Praziquantel (PZQ) is the first-line drug used against schistosomiasis, one of the most common parasitic diseases in the world. A series of crystalline structures including two new polymorphs of the pure drug and a series of cocrystals of PZQ have been discovered and deposited in the Cambridge Structural Database (CSD). This work adds to the list of multicomponent forms of PZQ a relevant example of a racemic hemihydrate (PZQ-HH), obtainable from commercial PZQ (polymorphic Form A) through mechanochemistry. Noteworthy, the formation of the new hemihydrate strongly depends on the initial polymorphic form of PZQ and on the experimental conditions used. The new PZQ-HH has been fully characterized by means of HPLC, Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Hot-Stage Microscopy (SEM), Powder X-Ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), FT-IR, polarimetry, solid-state NMR (SS-NMR), solubility and intrinsic dissolution rate (IDR), and in vitro tests on Schistosoma mansoni adults. The crystal structure was solved from the powder X-ray diffraction pattern and validated by periodic-DFT calculations. The new bioactive hemihydrate was physically stable for three months and showed peculiar biopharmaceutical features including enhanced solubility and a double intrinsic dissolution rate in water in comparison to the commercially available PZQ Form A.


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 343
Author(s):  
Qi Zhou ◽  
Zhongchuan Tan ◽  
Desen Yang ◽  
Jiyuan Tu ◽  
Yezi Wang ◽  
...  

Aripiprazole (ARI) is a third-generation antipsychotic with few side effects but a poor solubility. Salt formation, as one common form of multicomponent crystals, is an effective strategy to improve pharmacokinetic profiles. In this work, a new ARI salt with adipic acid (ADI) and its acetone hemisolvate were obtained successfully, along with a known ARI salt with salicylic acid (SAL). Their comprehensive characterizations were conducted using X-ray diffraction and differential scanning calorimetry. The crystal structures of the ARI-ADI salt acetone hemisolvate and ARI-SAL salt were elucidated by single-crystal X-ray diffraction for the first time, demonstrating the proton transfer from a carboxyl group of acid to ARI piperazine. Theoretical calculations were also performed on weak interactions. Moreover, comparative studies on pharmaceutical properties, including powder hygroscopicity, stability, solubility, and the intrinsic dissolution rate, were carried out. The results indicated that the solubility and intrinsic dissolution rate of the ARI-ADI salt and its acetone hemisolvate significantly improved, clearly outperforming that of the ARI-SAL salt and the untreated ARI. The study presented one potential alternative salt of aripiprazole and provided a potential strategy to increase the solubility of poorly water-soluble drugs.


2013 ◽  
Vol 16 (4) ◽  
pp. 577 ◽  
Author(s):  
Ali Shayanfar ◽  
Hamed Ghavimi ◽  
Hamed Hamishekar ◽  
Abolghasem Jouyban

Purpose: Atorvastatin calcium (ATC) is classified as class II (low solubility and high permeability) compound according to the biopharmaceutical classification system. The amorphous form of ATC possesses higher solubility, dissolution rate, and bioavailability than its crystalline form. Coamorphous drug system is a new and emerging method to prepare stable amorphous forms, in this case leading to the improved stability of ATC in dissolution medium. Methods: In this study, coamorphous form of ATC and nicotinamide (ATC-NIC) was  prepared from solvent evaporation method and characterized using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and powder X-ray diffraction (PXRD). The intrinsic dissolution rate and solubility of ATC-NIC were determined along with plasma concentrations of ATC using HPLC after oral dosing in rats. Results: The crystalline ATC was converted to coamorphous form revealing a molecular interaction between ATC and NIC. The intrinsic dissolution rate, solubility and plasma concentration of coamorphous ATC-NIC are higher than those of crystalline ATC. ATC-NIC coamorphous system showed greater solution stability than those reported in the literature for amorphous ATC.   Conclusions: Coamorphous ATC-NIC has improved physicochemical and pharmacokinetic properties as compared to ATC. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Ahmed Mahmoud Abdelhaleem Ali ◽  
Mayyas Mohammad Ahmad Al-Remawi

Improving the physicochemical properties and oral bioavailability of quetiapine fumarate (QF) enabling enhanced antipsychotic attributes are the main aims of this research. The freeze dried solid dispersion strategy was adopted using nicotinamide (NIC) as highly soluble coformer. The prepared dispersions were characterized using scanning electron microscopy (SEM) differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Static disc intrinsic dissolution rate and ex vivo diffusion through intestinal tissues were conducted and compared to pure quetiapine fumarate. The results demonstrated a highly soluble coamorphous system formed between quetiapine fumarate and nicotinamide at 1 : 3 molar ratio through H-bonding interactions. The results showed >14-fold increase in solubility of QF from the prepared dispersions. Increased intrinsic dissolution rate (from 0.28 to 0.603 mg cm−2 min−1) and faster flux rate through duodenum (from 0.027 to 0.041 mg cm−2 h−1) and jejunum (0.027 to 0.036 mg cm−2 h−1) were obtained. The prepared coamorphous dispersion proved to be effective in improving the drug solubility and dissolution rate and ex vivo diffusion. Therefore, binary coamorphous dispersions could be a promising solution to modify the physicochemical properties, raise oral bioavailability, and change the biopharmaceutics classification (BCS) of some active pharmaceutical ingredients.


Author(s):  
Moon Rajkumar ◽  
Gattani Surendra

 Objective: The objective of this study was to increase the solubility and dissolution rate of paliperidone (PAL) by preparing its nanocrystals using different hydrophilic carriers by antisolvent precipitation technique.Methods: The nanoparticles (NP) were characterized for aqueous solubility, drug content, Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, particle size, and in vitro-in vivo analysis.Results: The results showed improved solubility and dissolution rate of NPs when compared to pure drug and physical mixture (PM). Solubility data showed a linear graph giving an indication that there is a gradual increase in the solubility profile of the drug with an increase in concentration of the carriers. At highest concentration, the solubility of NPs with Plasdone S630, Povidone K-25, and PVP K-30 found to be increased by 12 folds, 9 folds and 6 folds, respectively, as compared to pure drug. The release profile of NPs with Plasdone S630 in terms of dissolution efficiency at 60 min (DE60), initial dissolution rate (IDR), amount release in 15 min (Q15 min), and time for 75% release (t75%) shows better results when compared to pure drug, PM, and also NPs with povidone 25 and povidone 30. In vivo study reveals that optimized NPs elicited significant induction of cataleptic behavior which is the indication of antipsychotic agent(s) effect.Conclusion: The process antisolvent precipitation under constant stirring may be a promising method to produce stable PAL NPs with markedly enhanced solubility and dissolution rate due to nanonization with the increased surface area, improved wettability, and reduced diffusion pathway.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 493
Author(s):  
Alexandra Teleki ◽  
Olivia Nylander ◽  
Christel A.S. Bergström

The intrinsic dissolution rate (IDR) of active pharmaceutical ingredients (API) is a key property that aids in early drug development, especially selecting formulation strategies to improve dissolution and thereby drug absorption in the intestine. Here, we developed a robust method for rapid, medium throughput screening of IDR and established the largest IDR dataset in open literature to date that can be used for pharmaceutical computational modeling. Eighteen compounds with diverse physicochemical properties were studied in both fasted and fed state simulated intestinal fluids. Dissolution profiles were measured in small-scale experimental assays using compound suspensions or discs. IDR measurements were not solely linked to API solubility in either dissolution media. Multivariate data analysis revealed that IDR strongly depends on compound partitioning into bile salt and phospholipid micelles in the simulated intestinal fluids, a process that in turn is governed by API lipophilicity, hydrophobicity, and ionization.


Author(s):  
Pravin S Patil ◽  
Shashikant C Dhawale

 Objective: The purpose of the present investigation was to develop a nanosuspension to improve dissolution rate and oral bioavailability of ritonavir.Methods: Extended-release ritonavir loaded nanoparticles were prepared using the polymeric system by nanoprecipitation technique. Further, the effect of Eudragit RL100 (polymeric matrix) and polyvinyl alcohol (surfactant) was investigated on particle size and distribution, drug content, entrapment efficiency, and in vitro drug release from nanosuspension where a strong influence of polymeric contents was observed. Drug-excipient compatibility and amorphous nature of drug in prepared nanoparticles were confirmed by Fourier transform infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffraction studies, respectively.Results: Hydrophobic portions of Eudragit RL100 could result in enhanced encapsulation efficiency. However, increase in polymer and surfactant contents lead to enlarged particle size proportionately as confirmed by transmission electron microscopy. Nanosuspension showed a significant rise in dissolution rate with complete in vitro drug release as well as higher bioavailability in rats compared to the pure drug.Conclusion: The nanoprecipitation technique used in present research could be further explored for the development of different antiretroviral drug carrier therapeutics.


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