Most cited article - PubMed ID 23494815
Designing a dynamic dissolution method: a review of instrumental options and corresponding physiology of stomach and small intestine
The use of natural compounds is becoming increasingly popular among patients, and there is a renewed interest among scientists in nature-based bioactive agents. Traditionally, herbal drugs can be taken directly in the form of teas/decoctions/infusions or as standardized extracts. However, the disadvantages of natural compounds, especially essential oils, are their instability, limited bioavailability, volatility, and often irritant/allergenic potential. However, these active substances can be stabilized by encapsulation and administered in the form of nanoparticles. This brief overview summarizes the latest results of the application of nanoemulsions, liposomes, solid lipid nanoparticles, and nanostructured lipid carriers used as drug delivery systems of herbal essential oils or used directly for their individual secondary metabolites applicable in cancer therapy. Although the discussed bioactive agents are not typical compounds used as anticancer agents, after inclusion into the aforesaid formulations improving their stability and bioavailability and/or therapeutic profile, they indicated anti-tumor activity and became interesting agents with cancer treatment potential. In addition, co-encapsulation of essential oils with synthetic anticancer drugs into nanoformulations with the aim to achieve synergistic effect in chemotherapy is discussed.
- Keywords
- anticancer activity, essential oils, herbal drugs, liposomes, nanoemulsions, nanostructured lipid carriers, solid lipid nanoparticles,
- Publication type
- Journal Article MeSH
- Review MeSH
Inflammatory diseases, whether caused by excessive stress on certain tissues/parts of the body or arising from infections accompanying autoimmune or secondary diseases, have become a problem, especially in the Western world today. Whether these are inflammations of visceral organs, joints, bones, or the like, they are always a physiological reaction of the body, which always tries to eradicate noxious agents and restore tissue homeostasis. Unfortunately, this often results in damage, often irreversible, to the affected tissues. Nevertheless, these inflammatory reactions of the body are the results of excessive stress, strain, and the generally unhealthy environment, in which the people of Western civilization live. The pathophysiology and pathobiochemistry of inflammatory/autoimmune processes are being studied in deep detail, and pharmaceutical companies are constantly developing new drugs that modulate/suppress inflammatory responses and endogenous pro-inflammatory agents. In addition to new specifically targeted drugs for a variety of pro-inflammatory agents, a strategy can be found for the use of older drugs, which are formulated into special nanodrug delivery systems with targeted distribution and often modified release. This contribution summarizes the current state of research and development of nanoformulated anti-inflammatory agents from both conventional drug classes and experimental drugs or dietary supplements used to alleviate inflammatory reactions.
- Keywords
- anti-inflammatory drugs, drug delivery systems, experimental drugs, inflammation, nanoformulations, nanoparticles,
- Publication type
- Journal Article MeSH
- Review MeSH
Biorelevant dissolution instruments represent an important tool for pharmaceutical research and development. These instruments are designed to simulate the dissolution of drug formulations in conditions most closely mimicking the gastrointestinal tract. In this work, we focused on the optimization of dissolution compartments/vessels for an updated version of the biorelevant dissolution apparatus-Golem v2. We designed eight compartments of uniform size but different inner geometry. The dissolution performance of the compartments was tested using immediate release caffeine tablets and evaluated by standard statistical methods and principal component analysis. Based on two phases of dissolution testing (using 250 and 100 mL of dissolution medium), we selected two compartment types yielding the highest measurement reproducibility. We also confirmed a statistically ssignificant effect of agitation rate and dissolution volume on the extent of drug dissolved and measurement reproducibility.
- Keywords
- Golem, biorelevant, caffeine, dissolution, multivariate data analysis,
- MeSH
- Models, Biological * MeSH
- Equipment Design MeSH
- Chemistry, Pharmaceutical * MeSH
- Pharmacokinetics * MeSH
- Gastrointestinal Absorption MeSH
- Gastrointestinal Tract metabolism MeSH
- Multivariate Analysis MeSH
- Computer Simulation MeSH
- Solubility * MeSH
- Publication type
- Journal Article MeSH
Nanoparticles can be considered as a useful tool for improving properties of poorly soluble active ingredients. Hydrochlorothiazide (Class IV of the Biopharmaceutical Classification System) was chosen as a model compound. Antisolvent precipitation-solvent evaporation and emulsion solvent evaporation methods were used for preparation of 18 samples containing hydrochlorothiazide nanoparticles. Water solutions of surfactants sodium dodecyl sulfate, Tween 80 and carboxymethyl dextran were used in mass concentrations of 1%, 3% and 5%. Acetone and dichloromethane were used as solvents of the model compound. The particle size of the prepared samples was measured by dynamic light scattering. The selected sample of hydrochlorothiazide nanoparticles stabilized with carboxymethyl dextran sodium salt with particle size 2.6 nm was characterized additionally by Fourier transform mid-infrared spectroscopy and scanning electron microscopy. It was found that the solubility of this sample was 6.5-fold higher than that of bulk hydrochlorothiazide.
- Keywords
- dynamic light scattering, hydrochlorothiazide, infrared spectroscopy, nanoparticles, scanning electron microscopy, solubility,
- MeSH
- Dynamic Light Scattering MeSH
- Hydrochlorothiazide chemical synthesis chemistry MeSH
- Molecular Structure MeSH
- Nanoparticles chemistry MeSH
- Surface-Active Agents chemistry MeSH
- Drug Compounding methods MeSH
- Solvents chemistry MeSH
- Solubility MeSH
- Particle Size MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Hydrochlorothiazide MeSH
- Surface-Active Agents MeSH
- Solvents MeSH
Different batches of atorvastatin, represented by two immediate release formulation designs, were studied using a novel dynamic dissolution apparatus, simulating stomach and small intestine. A universal dissolution method was employed which simulated the physiology of human gastrointestinal tract, including the precise chyme transit behavior and biorelevant conditions. The multicompartmental dissolution data allowed direct observation and qualitative discrimination of the differences resulting from highly pH dependent dissolution behavior of the tested batches. Further evaluation of results was performed using IVIVC/IVIVR development. While satisfactory correlation could not be achieved using a conventional deconvolution based-model, promising results were obtained through the use of a nonconventional approach exploiting the complex compartmental dissolution data.
- MeSH
- Atorvastatin chemistry therapeutic use MeSH
- Chemistry, Pharmaceutical MeSH
- Gastrointestinal Tract drug effects physiology MeSH
- Humans MeSH
- Intestine, Small drug effects MeSH
- Drug Liberation * MeSH
- Equipment and Supplies MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Atorvastatin MeSH