The use of solid oral dosage forms depends on the degree of bioavailability of the active pharmaceutical ingredient. The rate and extent of the drug released from the dosage form and subsequently dissolved in the gastrointestinal fluids greatly affects its fate in the human body. In vitro dissolution test may provide an in-depth understanding of a drug formulation's behaviour in vivo, as long as it sufficiently simulates relevant gastrointestinal conditions. Therefore, the development of in vitro gastrointestinal systems, which reflects advanced technology and knowledge about the human body, is receiving considerable attention. This article is focused on the biorelevant dynamic apparatuses and their sophisticated design, overcoming many limitations of conventional dissolution devices and allowing a better correlation with in vivo behaviour of solid oral dosage forms.
Tři různé přípravky obsahující 240 mg verapamil hydrochloridu v potahované tabletě se zpomale-ným uvolňováním byly porovnány zaslepeným disolučním testem. Množství uvolněné účinné látkyz tablety i její dynamika se po třetí hodině disoluce u všech tří přípravků významně lišily. U pří-pravku C (originální přípravek Isoptin SR, výrobce Knoll) se po sedmi hodinách uvolnilo 92,2 %účinné látky. U generického přípravku A bylo toto množství ve srovnání s originálním přípravkemvyšší, a u generického přípravku B nižší. Pouze u originálního přípravku byla dynamika uvolňováníúčinné látky lineární. Nepravidelné a nelineární uvolňování účinné látky z tablety může mít zanásledek klinicky suboptimální účinnost a bezpečnost generických přípravků.
Three different products containing 240 mg of verapamil hydrochloride in a coated tablet withsustained release were compared using the blinded dissolution test. The amount of the activesubstance released from the tablet and its dynamics differed significantly with all three productsafter 3 hours of dissolution. With product C (Isoptin SR, a proprietary product manufactured byKnoll), 92,2 % of the active substance was released after seven hours. With generic products A andB, the amounts were higher and lower, respectively. The dynamics of release of the active substancewas linear only with the proprietary product. Irregular and non-linear rates of active substancerelease from the tablet may result in clinically suboptimal efficacy and safety of generic products.
Development of new pharmaceutical compounds and dosage forms often requires in vitro dissolution testing with the closest similarity to the human gastrointestinal (GI) tract. To create such conditions, one needs a suitable dissolution apparatus and the appropriate data on the human GI physiology. This review discusses technological approaches applicable in biorelevant dissolutions as well as the physiology of stomach and small intestine in both fasted and fed state, that is, volumes of contents, transit times for water/food and various solid oral dosage forms, pH, osmolality, surface tension, buffer capacity, and concentrations of bile salts, phospholipids, enzymes, and Ca(2+) ions. The information is aimed to provide clear suggestions on how these conditions should be set in a dynamic biorelevant dissolution test.
- MeSH
- Chemistry, Pharmaceutical methods MeSH
- Pharmacokinetics * MeSH
- Gastrointestinal Tract physiology MeSH
- Pharmaceutical Preparations chemistry MeSH
- Humans MeSH
- Solubility MeSH
- Intestine, Small physiology MeSH
- Stomach physiology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
The rising demands on discriminatory and prediction abilities of dissolution methods and the increasing complexity of new drug products are the main driving forces of the progress in this field. The research moves forward as imperfections and shortcomings of classical methods are being described, and where the capabilities of the contemporary methods are insufficient, new methods are being developed. The review discusses these advances with respect to the issues that currently draw the most attention, i.e. correct simulation of hydrodynamics and stress forces, maintenance of sink conditions, study of precipitation, use of biorelevant media and the employment of more physiologically relevant methods in general.
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
Burst drug release is often considered a negative phenomenon resulting in unexpected toxicity or tissue irritation. Optimal release of a highly soluble active pharmaceutical ingredient (API) from hypromellose (HPMC) matrices is technologically impossible; therefore, a combination of polymers is required for burst effect reduction. Promising variant could be seen in combination of HPMC and insoluble Eudragits® as water dispersions. These can be applied only on API/insoluble filler mixture as over-wetting prevention. The main hurdle is a limited water absorption capacity (WAC) of filler. Therefore, the object of this study was to investigate the dissolution behavior of levetiracetam from HPMC/Eudragit®NE matrices using magnesium aluminometasilicate (Neusilin® US2) as filler with excellent WAC. Part of this study was also to assess influence of thermal treatment on quality parameters of matrices. The use of Neusilin® allowed the application of Eudragit® dispersion to API/Neusilin® mixture in one step during high-shear wet granulation. HPMC was added extragranularly. Obtained matrices were investigated for qualitative characteristics, NMR solid-state spectroscopy (ssNMR), gel layer dynamic parameters, SEM, and principal component analysis (PCA). Decrease in burst effect (max. of 33.6%) and dissolution rate, increase in fitting to zero-order kinetics, and paradoxical reduction in gel layer thickness were observed with rising Eudragit® NE concentration. The explanation was done by ssNMR, which clearly showed a significant reduction of the API particle size (150-500 nm) in granules as effect of surfactant present in dispersion in dependence on Eudragit®NE amount. This change in API particle size resulted in a significantly larger interface between these two entities. Based on ANOVA and PCA, thermal treatment was not revealed as a useful procedure for this system.
- MeSH
- Administration, Oral MeSH
- Gels MeSH
- Polymethacrylic Acids administration & dosage chemistry metabolism MeSH
- Delayed-Action Preparations administration & dosage chemistry metabolism MeSH
- Magnetic Resonance Spectroscopy methods MeSH
- Excipients chemistry MeSH
- Solubility MeSH
- Silicates administration & dosage chemistry metabolism MeSH
- Aluminum Compounds administration & dosage chemistry metabolism MeSH
- Magnesium Compounds administration & dosage chemistry metabolism MeSH
- Drug Liberation MeSH
- Particle Size MeSH
- Publication type
- Journal Article MeSH
Modern pharmaceutical technology still seeks new excipients and investigates the further use in already known ones. An example is magnesium aluminometasilicate Neusilin® US2 (NEU), a commonly used inert filler with unique properties that are usable in various pharmaceutical fields of interest. We aimed to explore its application in hypromellose matrix systems (HPMC content 10-30%) compared to the traditionally used microcrystalline cellulose (MCC) PH 102. The properties of powder mixtures and directly compressed tablets containing individual fillers NEU or MCC, or their blend with ratios of 1.5:1, 1:1, and 0.5:1 were investigated. Besides the routine pharmaceutical testing, we have enriched the matrices' evaluation with a biorelevant dynamic dissolution study and advanced statistical analysis. Under the USP apparatus 2 dissolution test, NEU, individually, did not provide advantages compared to MCC. The primary limitations were the burst effect increase followed by faster drug release at the 10-20% HPMC concentrations. However, the biorelevant dynamic dissolution study did not confirm these findings and showed similarities in dissolution profiles. It indicates the limitations of pharmacopoeial methods in matrix tablet development. Surprisingly, the NEU/MCC blend matrices at the same HPMC concentration showed technologically advantageous properties. Besides improved flowability, tablet hardness, and a positive impact on the in vitro drug dissolution profile toward zero-order kinetics, the USP 2 dissolution data of the samples N75M50 and N50M50 showed a similarity to those obtained from the dynamic biorelevant apparatus with multi-compartment structure. This finding demonstrates the more predictable in vivo behaviour of the developed matrix systems in human organisms.
- Publication type
- Journal Article MeSH
This paper evaluates and compares the properties of directly compressible tabletting materials and matrix tablets containing a combination of α-lactose monohydrate and microcrystalline cellulose in the 3:1 ratio in a physical mixture and in a coprocessed dry binder. Tested parameters include flow properties, compressibility, compactibility and the rate of drug release from tablets. Compressibility is evaluated by means of the energy profile of the compression process. Compactibility is evaluated by means of the tensile strength of the tablets. Dissolution testing is done using the rotating basket method. Dissolution profiles are evaluated by non-linear regression analysis. Total energy of compression and plasticity values were higher in tabletting materials with the coprocessed dry binder. Increasing additions of polyvinyl alcohol decreased the values of total energy of compression, plasticity, tensile strength of tablets and drug release rate. Dissolution behaviour of tablets, which contained the physical mixture or coprocessed dry binder and the same amount of polyvinyl alcohol, was comparable.
- MeSH
- Cellulose chemistry MeSH
- Chemistry, Pharmaceutical methods MeSH
- Technology, Pharmaceutical methods MeSH
- Salicylic Acid administration & dosage chemistry MeSH
- Lactose chemistry MeSH
- Nonlinear Dynamics MeSH
- Tensile Strength MeSH
- Polyvinyl Alcohol chemistry MeSH
- Excipients chemistry MeSH
- Solubility MeSH
- Tablets MeSH
- Drug Liberation MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
The solubility of weakly basic drugs in passage through gastrointestinal tract leads to their pH-dependent release from extended release formulations and to lower drug absorption and bioavailability. The aim of this study was to modulate the micro-environmental pH of hypromellose/montanglycol wax matrices and to observe its influence on the release of weakly basic drug verapamil hydrochloride (VH) with a pH-dependent solubility with respect to gel layer formation and its dynamics. For this study, malic and succinic acids differing in their solubility and pKa were selected as pH modifiers. The dissolution studies were performed by the method of changing pH. Within the same conditions, pH, thickness, and penetration force of the gel layer were measured as well. From the PCA sub-model, it is evident that a higher acid concentration ensured lower gel pH and conditions for higher drug solubility, thus creating larger gel layer with smaller rigidity, resulting in higher VH release during the dissolution test. Incorporation of stronger and more soluble malic acid (100 mg/tablet) created the most acidic and the thickest gel layer through which a total of 74% of VH was released. Despite having lower strength and solubility, matrices containing succinic acid (100 mg/tablet) released a comparable 71% of VH in a manner close to zero-order kinetics. The thinner and less rigid gel layers of the succinic acid matrices allowed an even slightly faster VH release at pH 6.8 than from matrices containing malic acid. Thus acid solubility is more parametrically significant than acid pKa for drug release at pH 6.8.
- MeSH
- Hypromellose Derivatives * MeSH
- Gels MeSH
- Kinetics MeSH
- Hydrogen-Ion Concentration MeSH
- Delayed-Action Preparations chemistry MeSH
- Malates chemistry MeSH
- Multivariate Analysis MeSH
- Solubility MeSH
- Succinates chemistry MeSH
- Tablets MeSH
- Drug Liberation MeSH
- Verapamil administration & dosage chemistry metabolism MeSH
- Waxes * MeSH
- Publication type
- Journal Article MeSH
There is increasing pharmaceutical interest in deep eutectic solvents not only as a green alternative to organic solvents in drug manufacturing, but also as liquid formulation for drug delivery. The present work introduces a hydrophobic deep eutectic solvent (HDES) to the field of lipid-based formulations (LBF). Phase behavior of a mixture with 2:1 M ratio of decanoic- to dodecanoic acid was studied experimentally and described by thermodynamic modelling. Venetoclax was selected as a hydrophobic model drug and studied by atomistic molecular dynamics simulations of the mixtures. As a result, valuable molecular insights were gained into the interaction networks between the different components. Moreover, experimentally the HDES showed greatly enhanced drug solubilization compared to conventional glyceride-based vehicles, but aqueous dispersion behavior was limited. Hence surfactants were studied for their ability to improve aqueous dispersion and addition of Tween 80 resulted in lowest droplet sizes and high in vitro drug release. In conclusion, the combination of HDES with surfactant(s) provides a novel LBF with high pharmaceutical potential. However, the components must be finely balanced to keep the integrity of the solubilizing HDES, while enabling sufficient dispersion and drug release.
- MeSH
- Chemistry, Pharmaceutical methods MeSH
- Hydrophobic and Hydrophilic Interactions * MeSH
- Lauric Acids chemistry MeSH
- Lipids * chemistry MeSH
- Oils chemistry MeSH
- Polysorbates chemistry MeSH
- Surface-Active Agents * chemistry MeSH
- Drug Compounding * methods MeSH
- Solvents * chemistry MeSH
- Solubility * MeSH
- Molecular Dynamics Simulation * MeSH
- Sulfonamides chemistry administration & dosage MeSH
- Drug Liberation * MeSH
- Publication type
- Journal Article MeSH
