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1.
Int J Pharm ; 644: 123294, 2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37544387

RESUMEN

Amorphous solid dispersions (ASD) represent a viable formulation strategy to improve dissolution and bioavailability of poorly soluble drugs. Our study aimed to evaluate the feasibility and potential role of hydrogenated phospholipid (HPL) as a matrix material and solubilizing additive for binary (alone) or ternary (in combination with polymers) solid dispersions, using fenofibrate (FEN) as the model drug. FEN, incorporated within ASDs by melting or freeze-drying (up to 20% m/m), stayed amorphous during short-term stability studies. The solubility enhancing potential of HPL depended on the dissolution medium. In terms of enhancing in vitro permeation, solid dispersions with HPL were found equally or slightly more potent as compared to the polymer-based ASD. For studied ASD, in vitro permeation was found substantially enhanced as compared to a suspension of crystalline FEN and at least equal compared to marketed formulations under comparable conditions (literature data). Additionally, while the permeation of neat FEN and FEN in binary solid dispersions was affected by the dissolution medium (i.e., the "prandial state"), for ternary solid dispersions the permeation was independent of the "prandial state" (FaSSIF = FeSSIF). This suggests that ternary solid dispersions containing both polymer and HPL may represent a viable formulation strategy to mitigate fenofibrate's food effect.


Asunto(s)
Productos Biológicos , Fenofibrato , Fenofibrato/química , Excipientes , Fosfolípidos , Polímeros/química , Preparaciones Farmacéuticas , Solubilidad
2.
Pharmaceutics ; 15(2)2023 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-36839914

RESUMEN

Replacing in vivo with in vitro studies can increase sustainability in the development of medicines. This principle has already been applied in the biowaiver approach based on the biopharmaceutical classification system, BCS. A biowaiver is a regulatory process in which a drug is approved based on evidence of in vitro equivalence, i.e., a dissolution test, rather than on in vivo bioequivalence. Currently biowaivers can only be granted for highly water-soluble drugs, i.e., BCS class I/III drugs. When evaluating poorly soluble drugs, i.e., BCS class II/IV drugs, in vitro dissolution testing has proved to be inadequate for predicting in vivo drug performance due to the lack of permeability interpretation. The aim of this review was to provide solid proofs that at least two commercially available cell-free in vitro assays, namely, the parallel artificial membrane permeability assay, PAMPA, and the PermeaPad® assay, PermeaPad, in different formats and set-ups, have the potential to reduce and replace in vivo testing to some extent, thus increasing sustainability in drug development. Based on the literature review presented here, we suggest that these assays should be implemented as alternatives to (1) more energy-intense in vitro methods, e.g., refining/replacing cell-based permeability assays, and (2) in vivo studies, e.g., reducing the number of pharmacokinetic studies conducted on animals and humans. For this to happen, a new and modern legislative framework for drug approval is required.

3.
Drug Deliv Transl Res ; 13(5): 1288-1304, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36209313

RESUMEN

Lipid-based formulations (LBFs) are used by the pharmaceutical industry in oral delivery systems for both poorly water-soluble drugs and biologics. Digestibility is key for the performance of LBFs and in vitro lipolysis is commonly used to compare the digestibility of LBFs. Results from in vitro lipolysis experiments depend highly on the experimental conditions and formulation characteristics, such as droplet size (which defines the surface area available for digestion) and interfacial structure. This study introduced the intrinsic lipolysis rate (ILR) as a surface area-independent approach to compare lipid digestibility. Pure acylglycerol nanoemulsions, stabilized with polysorbate 80 at low concentration, were formulated and digested according to a standardized pH-stat lipolysis protocol. A methodology originally developed to calculate the intrinsic dissolution rate of poorly water-soluble drugs was adapted for the rapid calculation of ILR from lipolysis data. The impact of surfactant concentration on the apparent lipolysis rate and lipid structure on ILR was systematically investigated. The surfactant polysorbate 80 inhibited lipolysis of tricaprylin nanoemulsions in a concentration-dependent manner. Coarse-grained molecular dynamics simulations supported these experimental observations. In the absence of bile and phospholipids, tricaprylin was shielded from lipase at 0.25% polysorbate 80. In contrast, the inclusion of bile salt and phospholipid increased the surfactant-free area and improved the colloidal presentation of the lipids to the enzyme, especially at 0.125% polysorbate 80. At a constant and low surfactant content, acylglycerol digestibility increased with decreasing acyl chain length, decreased esterification, and increasing unsaturation. The calculated ILR of pure acylglycerols was successfully used to accurately predict the IRL of binary lipid mixtures. The ILR measurements hold great promise as an efficient method supporting pharmaceutical formulation scientists in the design of LBFs with specific digestion profiles.


Asunto(s)
Lípidos , Lipólisis , Lípidos/química , Polisorbatos/química , Glicéridos , Preparaciones Farmacéuticas , Tensoactivos/química , Agua , Solubilidad
4.
Eur J Pharm Sci ; 170: 106098, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-34954051

RESUMEN

The absorption of orally administered drug products is a complex, dynamic process, dependant on a range of biopharmaceutical properties; notably the aqueous solubility of a molecule, stability within the gastrointestinal tract (GIT) and permeability. From a regulatory perspective, the concept of high intestinal permeability is intrinsically linked to the fraction of the oral dose absorbed. The relationship between permeability and the extent of absorption means that experimental models of permeability have regularly been used as a surrogate measure to estimate the fraction absorbed. Accurate assessment of a molecule's intestinal permeability is of critical importance during the pharmaceutical development process of oral drug products, and the current review provides a critique of in vivo, in vitro and ex vivo approaches. The usefulness of in silico models to predict drug permeability is also discussed and an overview of solvent systems used in permeability assessments is provided. Studies of drug absorption in humans are an indirect indicator of intestinal permeability, but both in vitro and ex vivo tools provide initial screening approaches and are important tools for assessment of permeability in drug development. Continued refinement of the accuracy of in silico approaches and their validation with human in vivo data will facilitate more efficient characterisation of permeability earlier in the drug development process and will provide useful inputs for integrated, end-to-end absorption modelling.


Asunto(s)
Biofarmacia , Preparaciones Farmacéuticas , Administración Oral , Tracto Gastrointestinal/metabolismo , Humanos , Absorción Intestinal , Modelos Biológicos , Permeabilidad , Preparaciones Farmacéuticas/metabolismo , Solubilidad
5.
J Pharm Sci ; 111(1): 32-40, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34102204

RESUMEN

In order to achieve a high sample throughput, permeation experiments are often carried out using 96-well sandwich plates. Even though agitation is regarded as important, permeation studies in 96-well format are often carried out without agitation since orbital shaking, the most common agitation method for 96-well plates, has been reported to create difficulties (e.g., well-to-well cross-talk), and high cost and low availability limits the use of other agitation techniques (e.g., magnetic stirring). This study investigates how orbital shaking and magnetic stirring affect the apparent permeability of model compounds with different water-solubilities (methylene blue, carbamazepine, and albendazole) using a novel 96-well sandwich plate comprising a cellulose-hydrate membrane (PermeaPlain® plate). Orbital shaking was found less efficient than magnetic stirring in terms of homogeneously distributing a small volume of dye within the donor compartment. Furthermore, in terms of achieving maximum trans-barrier flux, magnetic stirring was found a more effective agitation method than orbital shaking. Obviously, with orbital shaking the medium in the bottom compartment of the sandwich plates never was mixed in-phase. The impact of insufficient mixing on permeation was found strongest with the most lipophilic compound, which correlates with literature reports that the contribution of the unstirred water layer towards the overall resistance of the barrier is most expressed in case of lipophilic drugs. Finally, it was tested how different liquid volumes in the bottom compartment of the plates affect the well-to-well cross-talk during permeation experiments under orbital shaking. This study revealed that 250-300 µL should be used in the bottom compartment of the sandwich plates to reduce well-to-well cross-talk when using orbital shaking for agitation.


Asunto(s)
Alimentos , Agua , Medios de Cultivo , Permeabilidad , Solubilidad
6.
J Pharm Sci ; 110(1): 198-207, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32827494

RESUMEN

Phospholipids are amphiphilic lipids with versatile properties making them promising excipients for enabling formulations for oral drug delivery. Unfortunately, systematic studies on how phospholipid type and content affect oral absorption are rare. Often, only one phospholipid type is used for the formulation development and only one formulation, optimized according to in vitro parameters, is included in oral bioavailability studies. Using this approach, it is unclear if a certain in vitro parameter is predictive for the in vivo performance. In this study, a labor-saving in vitro permeation screening method was combined with a pharmacokinetic study in rats to for the first time systematically compare two types of phospholipid-based solid dispersions. The dispersions contained the drug celecoxib and monoacyl or diacyl phosphatidylcholine at different drug-to-phospholipid ratios. The in vitro screening revealed: 1) none of the formulations with high phospholipid content increased permeation, 2) phospholipid content was negatively correlated with permeation, and 3) mono and diacyl-phosphatidylcholine formulations performed equally. The pharmacokinetic study revealed: 1) At low phospholipid content absorption was enhanced, 2) phospholipid content was negatively correlated with absorption, and 3) monoacyl and diacyl phosphatidylcholine formulations performed equally. Apart from the reference (suspension), the in vitro permeation screening thus predicted the formulations in vivo performance.


Asunto(s)
Preparaciones Farmacéuticas , Fosfolípidos , Administración Oral , Animales , Disponibilidad Biológica , Celecoxib , Excipientes , Ratas , Solubilidad
7.
Eur J Pharm Sci ; 152: 105452, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32622980

RESUMEN

Supersaturated lipid-based drug delivery systems have recently been investigated for oral administration for a variety of lipophilic drugs and have shown either equivalent or superior oral bioavailability compared to conventional non-supersaturated lipid-based drug delivery systems. The aim of the present work was to explore supersaturated versus non-supersaturated lipid-based systems at equivalent lipid doses, on in vivo bioavailability in rats and on in vitro permeation across a biomimetic PermeapadⓇ membrane to establish a potential in vivo - in vitro correlation. A secondary objective was to investigate the influence of lipid composition on in vitro and in vivo performance of lipid systems. Results obtained indicated that increasing the celecoxib load in the lipid-based formulations by thermally-induced supersaturation resulted in increased bioavailability for medium and long chain mono-/di-glycerides systems relative to their non-supersaturated (i.e. 85%) reference formulations, albeit only significant for the medium chain systems. Long chain systems displayed higher celecoxib bioavailability than equivalent medium chain systems, both at supersaturated and non-supersaturated drug loads. In vitro passive permeation of celecoxib was studied using both steady-state and dynamic conditions and correlated well with in vivo pharmacokinetic results with respect to compositional effects. In contrast, permeation studies indicated that flux and percentage permeated of supersaturated systems, either at steady-state or under dynamic conditions, decreased or were unchanged relative to non-supersaturated systems. This study has shown that by using two cell-free PermeapadⓇ permeation models coupled with rat-adapted gastro-intestinal conditions, bio-predictive in vitro tools can be developed to be reflective of in vivo scenarios. With further optimization, such models could be successfully used in pharmaceutical industry settings to rapidly screen various prototype formulations prior to animal studies.


Asunto(s)
Sistemas de Liberación de Medicamentos , Lípidos , Administración Oral , Animales , Disponibilidad Biológica , Celecoxib , Ratas , Solubilidad
8.
Pharm Res ; 37(6): 93, 2020 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-32394114

RESUMEN

PURPOSE: Here, first experiences with a prototype tool for high throughput (passive) permeability profiling, a 96-well plate comprising the Permeapad® membrane, are reported. The permeabilities of a set of drugs were determined and compared to published measures of oral absorption, such as human fraction absorbed (Fa) and in vitro permeability values obtained using other tools. METHODS: The tool consists of a 96-well bottom and screen plate with the artificial, phospholipid-based barrier (Permeapad®) mounted between the plates' lower and upper compartments. The permeability of 14 model compounds including high- and low-absorption drugs, cationic, anionic, zwitterionic and neutral molecules, was determined by quantifying the compounds' transport over time, deriving the steady-state flux from the linear part of the cumulative curves and calculating the apparent permeability (Papp). The membrane structure was investigated in a high-resolution digital light microscope. RESULTS: The Permeapad® 96-well plate was found suited to distinguish high and low absorption drugs and yielded a hyperbolic correlation to Fa. The Papp values obtained were congruent with those determined with in-house prepared Permeapad® in the Franz cell set-up. Furthermore, good to excellent correlations were seen with Caco-2 permeability (R2 = 0.70) and PAMPA permeability (R2 = 0.89). Microscopic investigation of the Permeapad® barrier revealed the formation of phospholipid vesicles and myelin figures in aqueous environment. CONCLUSION: The Permeapad® 96-well plate permeation set-up is a promising new tool for rapid and reproducible passive permeability profiling.


Asunto(s)
Portadores de Fármacos/química , Ensayos Analíticos de Alto Rendimiento/métodos , Preparaciones Farmacéuticas/metabolismo , Fosfolípidos/química , Células CACO-2 , Humanos , Membranas Artificiales , Modelos Biológicos , Modelos Químicos , Estructura Molecular , Permeabilidad , Polivinilos/química , Soluciones/química , Relación Estructura-Actividad
9.
Pharmaceutics ; 11(5)2019 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-31083433

RESUMEN

Early formulation screening can alleviate development of advanced oral drug formulations, such as amorphous solid dispersions (ASDs). Traditionally, dissolution is used to predict ASD performance. Here, a high-throughput approach is described that simultaneously screens drug dissolution and permeation employing a two-compartment 96-well plate. Freeze-drying from hydro-alcoholic solutions was used to prepare amorphous formulations. The screening approach was tested on amorphous and crystalline tadalafil formulations with and without Soluplus®. The workflow consisted of: 1) dispersion of the formulations; 2) incubation within the two-compartment plate, where a dialysis membrane separated donor (dispersed formulation) and acceptor; 3) sampling (donor and acceptor), where donor samples were centrifuged to remove non-dissolved material; and 4) quantification by UHPLC-UV. To identify optimal screening conditions, the following parameters were varied: dispersion medium (buffer / biomimetic media), acceptor medium (buffer / surfactant solutions), and incubation time (1, 3, and 6 h). Surfactants (acceptor) increased tadalafil permeation. Biomimetic medium (donor) enhanced dissolution, but not permeation, except for freeze-dried tadalafil, for which the permeated amount increased. The predictiveness was evaluated by comparing dissolution-/permeation-results with in vivo bioavailability. In general, both dissolution and permeation reflected bioavailability, whereof the latter was a better predictor. High-throughput dissolution/permeation is regarded promising for formulation screening.

10.
Eur J Pharm Sci ; 127: 199-207, 2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30408522

RESUMEN

The current study documents enhanced apparent solubility of the BCS class II drug celecoxib (CXB) when formulated as solid phospholipid dispersion (SPD) with either mono- or diacyl-phospholipids by freeze drying from hydro-alcoholic solvent. The enhanced solubility upon dispersion in buffer or fasted state simulated intestinal fluid (FaSSIF) is interpreted to be due to two effects: (1) amorphization of CXB, inducing supersaturation, which is also observed when CXB is freeze dried in the absence of phospholipids and (2) association of CXB with spontaneously forming colloidal structures, such as vesicles and/or micelles, promoting solubilization. The latter effect depended on the CXB-to-phospholipid ratio, where monoacyl-phospholipid was a more efficient solubilizer than diacyl-phospholipid. In the case of diacyl-phospholipid, solubilization also depended strongly on the dispersion medium, where FaSSIF induced a more pronounced solubilization effect than buffer. In contrast, a significantly enhanced in-vitro permeability of CXB across a biomimetic barrier (Permeapad®) was found only with low lipid contents up to a CXB to phospholipid mass-ratio of 1:10 or in the absence of phospholipid; above this critical ratio, permeability was not enhanced, i.e. comparable to that observed with a suspension of non-processed (crystalline) drug. This non-linear dissolution-/permeation-behavior was observed independently of (1) the type of phospholipid (monoacyl- or diacyl-) employed and (2) the dispersion medium (buffer or FaSSIF), despite the fact that different patterns of co-existing colloidal states were observed from mono-/diacyl-phospholipid formulations in buffer/FaSSIF (small bile salt micelles, intermediate size mixed micelles and large vesicular structures), assessed by asymmetric flow field-flow fractionation/multi angle laser light scattering. A uniform mechanistic hypothesis is presented to describe the impact of phospholipids on CXB permeation behavior: Obviously, the critical drug-to-phospholipid ratio represents a compromise between optimal stabilization of the amorphous state-induced supersaturation and reduced thermodynamic activity of CXB due to association with colloidal states, where the type of colloidal state (vesicle or micelle) appears to be of minor importance.


Asunto(s)
Celecoxib/química , Fosfolípidos/química , Liofilización , Secreciones Intestinales/química , Solubilidad
11.
Eur J Pharm Sci ; 119: 219-233, 2018 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-29660464

RESUMEN

Cell-free permeation systems are gaining interest in drug discovery and development as tools to obtain a reliable prediction of passive intestinal absorption without the disadvantages associated with cell- or tissue-based permeability profiling. Depending on the composition of the barrier, cell-free permeation systems are classified into two classes including (i) biomimetic barriers which are constructed from (phospho)lipids and (ii) non-biomimetic barriers containing dialysis membranes. This review provides an overview of the currently available cell-free permeation systems including Parallel Artificial Membrane Permeability Assay (PAMPA), Phospholipid Vesicle-based Permeation Assay (PVPA), Permeapad®, and artificial membrane based systems (e.g. the artificial membrane insert system (AMI-system)) in terms of their barrier composition as well as their predictive capacity in relation to well-characterized intestinal permeation systems. Given the potential loss of integrity of cell-based permeation barriers in the presence of food components or pharmaceutical excipients, the superior robustness of cell-free barriers makes them suitable for the combined dissolution/permeation evaluation of formulations. While cell-free permeation systems are mostly applied for exploring intestinal absorption, they can also be used to evaluate non-oral drug delivery by adjusting the composition of the membrane.


Asunto(s)
Absorción Intestinal , Preparaciones Farmacéuticas/metabolismo , Administración Oral , Animales , Humanos , Membranas Artificiales , Permeabilidad , Preparaciones Farmacéuticas/química , Fosfolípidos/metabolismo
12.
Eur J Pharm Sci ; 120: 61-72, 2018 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-29704643

RESUMEN

Colloidal phases (self-assemblies) in aqueous dispersions of selected binary bile salt/phospholipid blends were studied utilizing the combined analytical approach of asymmetrical flow field-flow fractionation (AF4) and multi-angle laser light scattering (MALLS) in order to resolve the co-existence of different colloidal assemblies. The binary blends were prepared by freeze-drying from tert-butanol/water co-solvent solutions. The blends contained one of two bile salts (sodium taurocholate (TC) or sodium glycodeoxycholate (GDX)) and a mono- or di-acyl phospholipid (lyso-phosphatidylcholine (L-PC) and phosphatidylcholine (PC), respectively). Bile salt and phospholipid (PL) concentrations and their respective ratios were varied systematically within the physiological range found in human intestinal fluids. Furthermore, the BCS class II drug Celecoxib was incorporated in selected blends to assess its potential impact on colloidal phases. To further investigate the smallest self-assemblies observed in AF4/MALLS analysis, dispersions of TC and GDX, respectively, were prepared and analyzed by dynamic light scattering (DLS). AF4/MALLS analysis revealed that binary bile-salt/phospholipid blends form three distinct particle fractions, when the concentration of bile-salt was sufficiently high (≥3.5 mM). Those fractions were assumed to be very small pure bile-salt dimeric/oligomeric self-assemblies (Ø ≈ 2-3 nm), mid-sized mixed micelles (Ø ≈ 10-50 nm) and large liposomes/aggregates (Ø ≈ 150-280 nm). If present, Celecoxib was found solubilized within the structures, but at the lowest TC concentration triggered the formation of an additional (vesicular) phase.


Asunto(s)
Celecoxib/química , Dispersión Dinámica de Luz , Fraccionamiento de Campo-Flujo , Ácido Glicodesoxicólico/química , Secreciones Intestinales/química , Rayos Láser , Lisofosfatidilcolinas/química , Fosfatidilcolinas/química , Dispersión de Radiación , Tensoactivos/química , Ácido Taurocólico/química , Tecnología Farmacéutica/métodos , Coloides , Digestión , Composición de Medicamentos , Micelas , Solubilidad
13.
Eur J Pharm Sci ; 108: 101-110, 2017 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-28108360

RESUMEN

Archaea contain membrane lipids that differ from those found in the other domains of life (Eukarya and Bacteria). These lipids consist of isoprenoid chains attached via ether bonds to the glycerol carbons at the sn-2,3 positions. Two types of ether lipids are known, polar diether lipids and bipolar tetraether lipids. The inherent chemical stability and unique membrane-spanning characteristics of tetraether lipids render them interesting for oral drug delivery purposes. Archaeal lipids form liposomes spontaneously (archaeosomes) and may be incorporated in conventional liposomes (mixed vesicles). Both types of liposomes are promising to protect their drug cargo, such as therapeutic peptides, against the acidic environment of the stomach and proteolytic degradation in the intestine. They appear to withstand lipolytic enzymes and bile salts and may thus deliver orally administered therapeutic peptides to distant sections of the intestine or to the colon, where they may be absorbed, eventually by the help of absorption enhancers. Archaeal lipids and their semisynthetic derivatives may thus serve as biological source for the next generation oral drug delivery systems. The aim of this review is to present a systematic overview over existing literature on archaea carrying diether and tetraether lipids, lipid diversity, means of lipid extraction and purification, preparation and in vitro stability studies of archaeal lipid-based liposomal drug carriers and in vivo proof-of concepts studies.


Asunto(s)
Archaea/química , Lípidos/química , Péptidos/administración & dosificación , Péptidos/química , Administración Oral , Animales , Química Farmacéutica , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Estabilidad de Medicamentos , Excipientes/química , Humanos , Lipoproteína Lipasa/química , Liposomas , Solubilidad , Comprimidos
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