scholarly journals CHARACTERIZATION OF DRUGS ENCAPSULATED INTO MESOPOROUS SILICA

Author(s):  
ARIF BUDIMAN

Solubility of the drug has a strong influence to achieve higher bioavailability of the drug in systemic circulation. More than 70% NCEs (new chemical entities) are hydrophobic, and practically difficult into solid formulation due to their poor water solubility. Mesoporous silicas (MSP) have been used for drug delivery system, especially for poorly water-soluble drugs. Encapsulation and interaction of drugs in MSP can enhance the delivery and maintain the stability of the drug. However, the characterization of the drug in MSP is necessary to confirm its molecular state. In this review, we present an overview of reports related to the characterization of drug encapsulated into MSP. Encapsulation of drugs in MSP can prevent recrystallization of drugs due to its inhibition of crystal nucleation. A porous material in MSP can maintain the drug in a physically stable amorphous state. The preventing of drug crystallization in MSP can enhance the solubility and the dissolution rate of drug. Therefore, in this work, attempts have been made to understand the molecular state of the drug in MSP. The physicochemical characterization of drug by transmission electron microscopy (TEM), scanning electron microscope (SEM), differential scanning calorimetry (DSC), fourier-transform infrared spectroscopy (FTIR), powder x-ray diffraction (PXRD) and thermogravimetric analysis (TGA) were discussed. The effect of solvent and methods of drug loading and the effect of the shape of MSP on release profiles are also presented. Overall, this review provides information about the characterization of drug encapsulated into MSP which will be useful in pharmaceutical formulation development.

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1140
Author(s):  
Silvana Alfei ◽  
Gabriella Piatti ◽  
Debora Caviglia ◽  
Anna Maria Schito

The growing resistance of bacteria to current chemotherapy is a global concern that urgently requires new and effective antimicrobial agents, aimed at curing untreatable infection, reducing unacceptable healthcare costs and human mortality. Cationic polymers, that mimic antimicrobial cationic peptides, represent promising broad-spectrum agents, being less susceptible to develop resistance than low molecular weight antibiotics. We, thus, designed, and herein report, the synthesis and physicochemical characterization of a water-soluble cationic copolymer (P5), obtained by copolymerizing the laboratory-made monomer 4-ammoniumbuthylstyrene hydrochloride with di-methyl-acrylamide as uncharged diluent. The antibacterial activity of P5 was assessed against several multi-drug-resistant clinical isolates of both Gram-positive and Gram-negative species. Except for strains characterized by modifications of the membrane charge, most of the tested isolates were sensible to the new molecule. P5 showed remarkable antibacterial activity against several isolates of genera Enterococcus, Staphylococcus, Pseudomonas, Klebsiella, and against Escherichia coli, Acinetobacter baumannii and Stenotrophomonas maltophilia, displaying a minimum MIC value of 3.15 µM. In time-killing and turbidimetric studies, P5 displayed a rapid non-lytic bactericidal activity. Due to its water-solubility and wide bactericidal spectrum, P5 could represent a promising novel agent capable of overcoming severe infections sustained by bacteria resistant the presently available antibiotics.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2196 ◽  
Author(s):  
Silvana Alfei ◽  
Anna Maria Schito ◽  
Guendalina Zuccari

Ursolic acid (UA) is a pentacyclic triterpenoid found in many medicinal plants and aromas endowed with numerous in vitro pharmacological activities, including antibacterial effects. Unfortunately, UA is poorly administered in vivo, due to its water insolubility, low bioavailability, and residual systemic toxicity, thus making urgent the development of water-soluble UA formulations. Dendrimers are nonpareil macromolecules possessing highly controlled size, shape, and architecture. In dendrimers with cationic surface, the contemporary presence of inner cavities and of hydrophilic peripheral functions, allows to encapsulate hydrophobic non-water-soluble drugs as UA, to enhance their water-solubility and stability, and to promote their protracted release, thus decreasing their systemic toxicity. In this paper, aiming at developing a new UA-based antibacterial agent administrable in vivo, we reported the physical entrapment of UA in a biodegradable not cytotoxic cationic dendrimer (G4K). UA-loaded dendrimer nanoparticles (UA-G4K) were obtained, which showed a drug loading (DL%) much higher than those previously reported, a protracted release profile governed by diffusion mechanisms, and no cytotoxicity. Also, UA-G4K was characterized by principal components analysis (PCA)-processed FTIR spectroscopy, by NMR and elemental analyses, and by dynamic light scattering experiments (DLS). The water solubility of UA-G4K was found to be 1868-fold times higher than that of pristine UA, thus making its clinical application feasible.


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.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2662
Author(s):  
Silvana Alfei ◽  
Chiara Brullo ◽  
Debora Caviglia ◽  
Guendalina Zuccari

2-(4-Bromo-3,5-diphenyl-pyrazol-1-yl)-ethanol (BBB4) was synthetized and successfully evaluated concerning numerous biological activities, except for antimicrobial and cytotoxic effects. Due to the antimicrobial effects possessed by pyrazole nucleus, which have been widely reported, and the worldwide need for new antimicrobial agents, we thought it would be interesting to test BBB4 and to evaluate its possible antibacterial effects. Nevertheless, since it is water-insoluble, the future clinical application of BBB4 will remain utopic unless water-soluble BBB4 formulations are developed. To this end, before implementing biological evaluations, BBB4 was herein re-synthetized and characterized, and a new water-soluble BBB4-based nano-formulation was developed by its physical entrapment in a biodegradable non-cytotoxic cationic dendrimer (G4K), without recovering harmful solvents as DMSO or surfactants. The obtained BBB4 nanoparticles (BBB4-G4K NPs) showed good drug loading (DL%), satisfying encapsulation efficiency (EE%), and a biphasic quantitative release profile governed by first-order kinetics after 24 h. Additionally, BBB4-G4K was characterized by ATR-FTIR spectroscopy, NMR, SEM, dynamic light scattering analysis (DLS), and potentiometric titration experiments. While, before the nanotechnological manipulation, BBB4 was completely water-insoluble, in the form of BBB4-G4K NPs, its water-solubility resulted in being 105-fold higher than that of the pristine form, thus establishing the feasibility of its clinical application.


2013 ◽  
Vol 295-298 ◽  
pp. 298-302
Author(s):  
Yan Zhang ◽  
Korbanjhon Brad

In this study, the inclusion complex of diosmetin with hydroxypropyl-β- -cyclodextrin (HP-β-CD) was prepared to improve the water solubility of diosmetin by the solvent method. The content of diosmetin in the complex was determined by UV. And the physicochemical properties of the complex were analyzed by ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC). The results showed that the physical phase of diosmetin had been changed. It was completely dispersed in HP-β-CD. HP-β-CD and diosmetin were combined by non-covalent bonds.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1606
Author(s):  
Debora Zanolla ◽  
Lara Gigli ◽  
Dritan Hasa ◽  
Michele R. Chierotti ◽  
Mihails Arhangelskis ◽  
...  

Two new solvates of the widely used anthelminthic Praziquantel (PZQ) were obtained through mechanochemical screening with different liquid additives. Specifically, 2-pyrrolidone and acetic acid gave solvates with 1:1 stoichiometry (PZQ-AA and PZQ-2P, respectively). A wide-ranging characterization of the new solid forms was carried out by means of powder X-ray diffraction, differential scanning calorimetry, FT-IR, solid-state NMR and biopharmaceutical analyses (solubility and intrinsic dissolution studies). Besides, the crystal structures of the two new solvates were solved from their Synchrotron-PXRD pattern: the solvates are isostructural, with equivalent triclinic packing. In both structures acetic acid and 2-pyrrolidone showed a strong interaction with the PZQ molecule via hydrogen bond. Even though previous studies have shown that PZQ is conformationally flexible, the same syn conformation as the PZQ Form A of the C=O groups of the piperazinone-cyclohexylcarbonyl segment is involved in these two new solid forms. In terms of biopharmaceutical properties, PZQ-AA and PZQ-2P exhibited water solubility and intrinsic dissolution rate much greater than those of anhydrous Form A.


2021 ◽  
Vol 18 ◽  
Author(s):  
Gabriela Hädrich ◽  
Cristiana Lima Dora ◽  
Gustavo Richter Vaz ◽  
Raphael Boschero ◽  
Arthur Sperry Appel ◽  
...  

Background: Lipid nanocarriers have been widely tested as drug delivery systems to treat diseases due to their bioavailability, controlled release, and low toxicity. For the pulmonary route, the Food and Drug Administration favors the use of substances generally recognized as safe, as well as biodegradable and biocompatible to minimize the possibility of toxicity. Tuberculosis (TB) remains a public health threat worldwide, mainly due to the long treatment duration and adverse effects. Therefore, new drug delivery systems to treat TB are needed. Objective: Physicochemical characterization of different lipid-based nanocarriers was used to optimize carrier properties. Optimized systems were incubated with Mycobacterium tuberculosis to assess whether lipid-based systems act as an energy source for the bacteria, which could be counterproductive to therapy. Method: Several excipients and surfactants were evaluated to prepare different types of nanocarriers using high-pressure homogenization. Results: A mixture of trimyristin with castor oil was chosen as the lipid matrix after differential scanning calorimetry analysis. A mixture of egg lecithin and PEG-660 stearate was selected as an optimal surfactant system as this mixture formed the most stable formulations. Three types of lipid nanocarriers, solid lipid nanoparticles, nanostructured lipid carriers (NLC), and Nano emulsions, were prepared, with the NLC systems showing the most suitable properties for further evaluation. It may provide the advantages of increasing the entrapment efficiency, drug release, and the ability to be lyophilized, producing powder for pulmonary administration being an alternative to entrap poor water-soluble molecules. Conclusion: Furthermore, the NLC system can be considered for use as a platform for the treatment of TB by the pulmonary route.


2019 ◽  
Vol 7 (4) ◽  
pp. 259-278 ◽  
Author(s):  
Kavita Joshi ◽  
Akhilesh Chandra ◽  
Keerti Jain ◽  
Sushama Talegaonkar

Most of the active pharmaceutical ingredient used in the management of disease have poor water solubility and offer grueling problems in drug formulation development since low solubility is generally associated with poor dissolution characteristics which leads to poor oral bioavailability. The great challenge for the development of a pharmaceutical product is to create its new formulation and drug delivery system to limit solubility problems of existing drug candidate. Limited drug-loading capacity requires a large amount of carrier material to get appropriate encapsulation of the drug, which is another major challenge in the development of pharmaceutical product which could be resolved by developing nanocrystals (NCs). A significant research in the past few years has been done to develop NCs which helps in the delivery of poorly water soluble drugs via different routes. The technology could continue to thrive as a useful tool in pharmaceutical sciences for the improvement of drug solubility, absorption and bioavailability. Many crystalline compounds have pulled in incredible consideration much of the time, due to their ability to show good physical and chemical properties when contrasted with their amorphous counterparts. Nanocrystals have been proven to show atypical properties compared to the bulk. This review article explores the principles of the important nanocrystallization techniques including NCs characterization and its application.


Author(s):  
Meka Lingam ◽  
Vobalaboina Venkateswarlu

The low aqueous solubility of celecoxib (CB) and thus its low bioavailability is a problem.    Thus, it is suggested to improve the solubility using cosolvency and solid dispersions techniques. Pure CB has solubility of 6.26±0.23µg/ml in water but increased solubility of CB was observed with increasing concentration of cosolvents like PEG 400, ethanol and propylene glycol. Highest solubility (791.06±15.57mg/ml) was observed with cosolvency technique containing the mixture of composition 10:80:10%v/v of water: PEG 400: ethanol. SDs with different polymers like PVP, PEG were prepared and subjected to physicochemical characterization using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), solubility and dissolution studies. These studies reveals that CB exists mainly in amorphous form in prepared solid dispersions of PVP, PEG4000 and PEG6000 further it can also be confirmed by solubility and dissolution rate studies. Solid dispersions of PV5 and PV9 have shown highest saturation solubility and dissolution rate


Author(s):  
Poovi Ganesan ◽  
N Damodharan

Background: A better understanding of the biopharmaceutical and physicochemical properties of drugs and the pharmaco-technical factors would be of great help for developing pharmaceutical products. But, it is extremely difficult to study the effect of each variable and interaction among them through the conventional approach Objective: To screen the most influential factors affecting the particle size (PS) of lipid nanoparticle (LNPs) (solid lipid nanoparticle (SLN) and nanostructured lipid carrier (NLC)) for poorly water-soluble BCS class-II drug like tamoxifen (TMX) to improve its oral bioavailability and to reduce its toxicity to tolerable limits using Taguchi (L12 (2 11)) orthogonal array design by applying computer optimization technique. Results: The size of all LNPs formulations prepared as per the experimental design varied between 172 nm and 3880 μm, polydispersity index between 0.033 and 1.00, encapsulation efficiency between 70.8% and 75.7%, and drug loading between 5.84% and 9.68%. The study showed spherical and non-spherical as well as aggregated and non-aggregated LNPs. Besides, it showed no interaction and amorphous form of the drug in LNPs formulation. The Blank NLCs exhibited no cytotoxicity on MCF-7 cells as compared to TMX solution, SLNs (F5) and NLCs (F12) suggests that the cause of cell death is primarily from the effect of TMX present in NLCs. Conclusions: The screening study clearly showed the importance of different individual factors significant effect for the LNPs formulation development and its overall performance in an in-vitro study with minimum experimentation thus saving considerable time, efforts, and resources for further in-depth study.


Sign in / Sign up

Export Citation Format

Share Document