scholarly journals Ternary Eutectic Ezetimibe–Simvastatin–Fenofibrate System and the Physical Stability of Its Amorphous Form

Author(s):  
Justyna Knapik-Kowalczuk ◽  
Daniel Kramarczyk ◽  
Karolina Jurkiewicz ◽  
Krzysztof Chmiel ◽  
Marian Paluch
Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1440
Author(s):  
Yanan Wang ◽  
Yong Wang ◽  
Jin Cheng ◽  
Haibiao Chen ◽  
Jia Xu ◽  
...  

The amorphous form of a drug usually exhibits higher solubility, faster dissolution rate, and improved oral bioavailability in comparison to its crystalline forms. However, the amorphous forms are thermodynamically unstable and tend to transform into a more stable crystalline form, thus losing their advantages. In order to investigate and suppress the crystallization, it is vital to closely monitor the drug solids during the preparation, storage, and application processes. A list of advanced techniques—including optical microscopy, surface grating decay, solid-state nuclear magnetic resonance, broadband dielectric spectroscopy—have been applied to characterize the physicochemical properties of amorphous pharmaceutical solids, to provide in-depth understanding on the crystallization mechanism. This review briefly summarizes these characterization techniques and highlights their recent advances, so as to provide an up-to-date reference to the available tools in the development of amorphous drugs.


2021 ◽  
Vol 11 ◽  
pp. 73-86
Author(s):  
Raghad Al Nuss ◽  
Hind El Zein

Objective: The objective of this research was to enhance the physical stability and the dissolution rate of cefdinir, a BCS class IV drug, characterized by low and variable bioavailability due to both its low solubility and low permeability. Methods: Cefdinir was loaded into the mesoporous silica (SBA-15), by using the solvent immersion method starting from different organic solvents. And then formula (F3), which exhibited the highest loading percentage, was selected to study its drug release in media with different pH (1.2, 4.5, and 6.8), and has been fully characterized by using: Fourier Transform Infrared Spectroscopy (FT-IR) Spectroscopy, Differential Scanning Calorimetry, Powder X-ray Diffraction, and has been subjected to accelerated stability tests using different temperatures and relative humidity. Drug release kinetics were studied by using the following models: Probit, Gompertz, Weibull, and Logistic. Results: The results showed a remarkable dissolution improvement of cefdinir from the loaded silica in comparison to the crystalline drug at the different studied media. Drug release behaviors were well simulated by the Weibull model for F3 in all studied media and for pure Cefdinir in phosphate buffer only, and by the Gompertz function for pure Cefdinir in HCl buffer and Acetate buffer. FTIR results showed hydrogen bonds formed between the drug and silica, DSC and PXRD results revealed the transformation of cefdinir into an amorphous form upon adsorption. Stability studies under different conditions revealed the ability of mesoporous silica to maintain the amorphous state of the drug, which has been formed upon adsorption, and to prevent re-organization in the crystal nucleus of the drug molecules. Conclusion: Thus, loading cefdinir onto mesoporous silica can be used as a promising method to enhance drug dissolution, and maintain the physical stability of its amorphous form.


Author(s):  
Noorma Rosita ◽  
Dewi Haryadi ◽  
Tristiana Erawati ◽  
Rossa Nanda ◽  
Widji Soeratri

The aim of this study was to investigate the ability of NLC in increasing photostability of tomato extract in term of antioxidant activity. Photostability testing on antioxidant activity of samples were conducted by accelerating method using UVB radiation 32.400 joule for 21 hours radiation. Antioxidant activity was measured by DPPH method. NLC was made by High Shear Homogenization (HPH) method at 24000 rpm for 4 cycles, while conventional creame was made by low speed at 400 rpm. The product were characterized include: pH, viscosity, and particle size. There were had difference characters and physical stability. NLC had smaller size, more homogenous and more stable than conventional creame. It was known that stability of antioxidant activity of tomato extract in NLC system higher than in conventional creame. That was showed with k value, as constanta of rate scavenging activity decreasing in antioxidant power between time (Sigma 2-tail less than 0.005) of NLC and conventional creame were: 2.03x10-2 %/hour ±0.08 (3.94) and 4.71x 10-2 %/ hour ±0.23 (4.88) respectively.


Author(s):  
Kathpalia Harsha ◽  
Das Sukanya

Ion Exchange Resins (IER) are insoluble polymers having styrene divinylbenzene copolymer backbone that contain acidic or basic functional groups and have the ability to exchange counter ions with the surrounding aqueous solutions. From the past many years they have been widely used for purification and softening of water and in chromatographic columns, however recently their use in pharmaceutical industry has gained considerable importance. Due to the physical stability and inert nature of the resins, they can be used as a versatile vehicle to design several modified release dosage forms The ionizable drug is complexed with the resin owing to the property of ion exchange. This resin complex dissociatesin vivo to release the drug. Based on the dissociation strength of the drug from the drug resin complex, various release patterns can be achieved. Many formulation glitches can be circumvented using ion exchange resins such as bitter taste and deliquescence. These resins also aid in enhancing disintegrationand stability of formulation. This review focuses on different types of ion exchange resins, their preparation methods, chemistry, properties, incompatibilities and their application in various oral drug delivery systems as well as highlighting their use as therapeutic agents.


2020 ◽  
Vol 10 (2) ◽  
pp. 53-59
Author(s):  
Bharathi M ◽  
Mullaikodi O ◽  
Rajalingam D ◽  
Gnanasekar N ◽  
Kesavan M

A Microsponge (MS) is an extremely interconnected, permeable, polymeric structure that involves permeable microparticles trapping and discharging through the skin for a considerable time period. Drug delivery system (DDS) offer extended discharge with less degradation, improved physical stability along with better tolerance. The main intend of any DDS is to achieve the required amount of drug in plasma to produce the desired therapeutic and non-poisonous effect over a prolonged period of time. Specific methods for preparing MS were reviewed in this current investigation, and their pharmaceutical implementations were signed. MS have major DDS point of interest. It also improves stability, increased flexibility in formulation and increased elegance. In fact, numerous studies have reported that MS supplies are not allergic, mutagenic, and poisonous. MS creativity is used in products such as sunscreen, prescription, cosmetics, and OTC skin care. This inquiry primarily focuses on the different methods used to identify, plan and exploit MS.


Author(s):  
Narendar D ◽  
Ettireddy S

The content of this investigation was to study the influence of β-cyclodextrin and hydroxy propyl-β-cyclodextrin complexation on enhancement of solubility and dissolution rate of isradipine. Based on preliminary phase solubility studies, solid complexes prepared by freeze drying method in 1:1 molar ratio were selected and characterized by DSC for confirmation of complex formation. Prepared solid dispersions were evaluated for drug content, solubility and in vitro dissolution. The physical stability of optimized formulation was studied at refrigerated and room temperature for 2 months. Solid state characterization of optimized complex performed by DSC and XRD studies.  Dissolution rate of isradipine was increased compared with pure drug and more with HP-β-CD inclusion complex than β-CD. DSC and XRD analyzes that drug was in amorphous form, when the drug was incorporated as isradipine β-CD and HP-β-CD inclusion complex. Stability studies resulted in low or no variations in the percentage of complexation efficiency suggesting good stability of molecular complexes. The results conclusively demonstrated that the enhancement of solubility and dissolution rate of isradipine by drug-cyclodextrin complexation was achieved.   


Author(s):  
Kishan Veerabrahma ◽  
Swapna Madishetty ◽  
Muzammil Afzal Syed ◽  
Prabhakar Kandadi

Cationic nanoemulsions were reported to have increased bioavailability. The aim of present study was to prepare a cationic lipid nanoemulsion of diclofenac acid (LNEs) for improved oral bioavailability to treat arthritic conditions. The LNEs of diclofenac acid were prepared by using soya bean oil, egg lecithin, cholesterol and stearylamine. Stearylamine was used as positive charge inducer. The LNEs were processed by homogenization and ultrasonication. The formulation composition was selected based on earlier reports. The LNEs were characterized for size and zeta potential. The physical stability of LNEs was studied using autoclaving, centrifugal, desorption (dilution effect) stresses and on storage. The total drug content and entrapment efficiency were determined using HPLC. During in vivo studies in Wistar rats, the pharmacokinetic parameters of LNEs were compared with a prepared diclofenac suspension in sodium CMC mucilage. The selected formulations, F1, F2 and F3, were relatively stable during centrifugal stress, dilution stress and on storage. The drug content was found to be 2.38 ± 1.70 mg/ml for F1, 2.30 ± 0.82 mg/ml for F2, and 2.45 ± 0.66 mg/ml for F3. The entrapment efficiencies were 97.83 ± 0.53%, 97.87 ± 1.22% and 98.25 ± 0.21% for F1, F2 and F3 respectively. The cumulative percentage drug release from F1, F2 and F3 showed more release in pH 6.8 phosphate buffer than in pH 1.2 HCl. During oral bioavailability studies, the LNEs showed higher serum concentrations than a suspension. The relative bioavailability of the LNE formulations F1, F2 and F3 were found to be 2.35, 2.94 and 6.28 times that of F4 suspension and were statistically significant. Of all, the cationic lipid nanoemulsion (F3) was superior in improving bioavailability, when compared with plain emulsion (F1) and cholesterol containing LNE (F2). The study helps in designing the cationic oral nanoemulsions to improve the oral bioavailability of diclofenac.


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