International Journal of Pharmaceutics (v.508, #1-2)
EDITORIAL BOARD (iii).
Systemic delivery of artemether by dissolving microneedles by Yuqin Qiu; Chun Li; Suohui Zhang; Guozhong Yang; Meilin He; Yunhua Gao (1-9).
Display OmittedDissolving microneedles (DMNs) based transdermal delivery is an attractive drug delivery approach with minimal invasion. However, it is still challenging to load poorly water-soluble drugs in DMNs for systemic delivery. The aim of the study was to develop DMNs loaded with artemether (ARM) as a model drug, to enable efficient drug penetration through skin for systemic absorption and distribution. The micro-conduits created by microneedles were imaged by confocal laser scanning microscopy (CLSM), and the insertion depth was suggested to be about 270 μm. The maximum amount of ARM delivered into skin was 72.67 ± 2.69% of the initial dose loaded on DMNs preparation. Pharmacokinetics study in rats indicated a dose-dependent profile of plasma ARM concentrations, after ARM-loaded DMNs treatment. In contrast to intramuscular injection, DMNs application resulted in lower peak plasma levels, but higher plasma ARM concentration at 8 h after administration. There were no significant difference in area under the curve and bioavailability between DMNs group and intramuscular group (P > 0.05). Pharmacodynamics studies performed in collagen-induced arthritis (CIA) rats showed that ARM-loaded DMNs could reverse paw edema, similar to ARM intramuscular injection. In conclusion, developed DMNs provided a potential minimally invasive route for systemic delivery of poorly water-soluble drugs.
Keywords: Dissolving microneedles; Artemether; Poorly water-soluble drugs; Intradermal delivery;
Poly(ε-caprolactone)/triclosan loaded polylactic acid nanoparticles composite: A long-term antibacterial bionanocomposite with sustained release by Babak Kaffashi; Saeed Davoodi; Erfan Oliaei (10-21).
Display OmittedIn this study, the antibacterial bionanocomposites of poly(ε-caprolactone) (PCL) with different concentrations of triclosan (TC) loaded polylactic acid (PLA) nanoparticles (30 wt% triclosan) (LATC30) were fabricated via a melt mixing process in order to lower the burst release of PCL and to extend the antibacterial activity during its performance. Due to the PLA's higher glass transition temperature (Tg) and less flexibility compared with PCL; the PLA nanoparticles efficiently trapped the TC particles, reduced the burst release of TC from the bionanocomposites; and extended the antibacterial property of the samples up to two years. The melt mixing temperature was adjusted to a temperature lower than the melting point of LATC30 nanoparticles; therefore, these nanoparticles were dispersed in the PCL matrix without any chemical reaction and/or drug extraction. The sustained release behavior of TC from PCL remained unchanged since no significant changes occurred in the samples’ crystallinity compared with that in the neat PCL. The elastic moduli of samples were enhanced once LATC30 is included. This is necessary since the elastic modulus is decreased with water absorption. The rheological behaviors of samples showed appropriate properties for melt electro-spinning. A stable process was established as the relaxation time of the bionanocomposites was increased. The hydrophilic properties of samples were increased with increasing LATC30. The proliferation rate of the fibroblast (L929) cells was enhanced as the content of nanoparticles was increased. A system similar to this could be implemented to prepare long-term antibacterial and drug delivery systems based on PCL and various low molecular weight drugs. The prepared bionanocomposites are considered as candidates for the soft connective tissue engineering and long-term drug delivery.
Keywords: Poly(ε-caprolactone); Drug release; Bionanocomposite; Polylactic acid; Triclosan; Antibacterial;
Expression of P-glycoprotein in excised human nasal mucosa and optimized models of RPMI 2650 cells by Anne M. Dolberg; Stephan Reichl (22-33).
Display OmittedTo assess the transmucosal drug transport in the development of medications for intranasal administration, cellular in vitro models are preferred over the use of animal tissues due to inter-species variations and ethical concerns. With regard to the distribution of active agents and multidrug resistance, the ABC transporter P-glycoprotein plays a major role in several mammalian tissues. The present study compares the expression of this efflux pump in optimized in vitro models based on the human RPMI 2650 cell line with specimens of human turbinate mucosa. The presence of the ABCB1 gene was investigated at the mRNA and protein levels using RT-PCR and Western blot analysis in differently cultured RPMI 2650 cells and excised human nasal epithelium. Furthermore, the localization and activity of P-gp was examined by immunohistochemical staining and functionality assays using different substrates in both in vitro and ex vivo models. Both mRNA and protein expression of P-gp was found in all studied models. Furthermore, transporter functionality was detected in both RPMI 2650 cell culture models and excised human mucosa. The results demonstrated a highly promising comparability between RPMI 2650 models and explants of human nasal tissue concerning the influence of MDR1 on drug disposition. The RPMI 2650 cell line might become a useful tool in preclinical trials to improve reproducibility and achieve greater applicability to humans of experimental data regarding passive diffusion and active efflux of drug candidates.
Keywords: RPMI 2650 cell line; Human nasal mucosa; ABC transporter; P-glycoprotein; Active efflux; In vitro model; Drug delivery;
A flexible polymersome system with tunable morphology and release profiles for efficient intracellular delivery by Tsuf Croitoru-Sadger; Yael Leichtmann-Bardoogo; Boaz Mizrahi (34-41).
Display OmittedPolymersomes are widely used as drug delivery system however they have shortcomings in drug-eluting properties that are attributable to the high molecular weight of the copolymers forming their membrane. Here we demonstrate for the first time how novel class of polymersomes from very short, liquid to soft star-shaped copolymers can be empowered to form an efficient drug delivery system. The copolymers undergo self-assembly in water into a stable, nano-sized rod or a spherical shape polymersomes. Increasing the Mw of the hydrophobic moieties the CMC value is decreased accompanied with the tendency to form a more spherical structure. The poorly water-soluble anticancer drug camptothecin was loaded into the fabricated polymersomes, resulting in a high drug loading content, and released over a period of over three days. Furthermore, this biocompatible system could deliver a variety of drugs intracellularly in a rapid yet controlled manner. Therefore, this nano system’s tailorable properties, biocompatibility and ability to incorporate hydrophobic drugs and release them intracellularly are desirable traits for anti-cancer delivery system and other biomedical applications.
Keywords: Self-assembly; Polymersome; Camptothecin; PEG; Caprolactone;
Solid microcrystalline dispersion films as a new strategy to improve the dissolution rate of poorly water soluble drugs: A case study using olanzapine by Laura Modica de Mohac; Maria de Fátima Pina; Bahijja Tolulope Raimi-Abraham (42-50).
Display OmittedIn this study, we evaluate the dissolution rate enhancement of solid microcrystalline dispersion (SMD) films of olanzapine (OLZ) formulated with four water-soluble polymers namely poly(N-vinylpyrrolidone) (PVP), poloxamer 188 (P188), poloxamer 407 (P407) and Soluplus® (SLP). Prepared formulations were characterised to determine particle size, morphology, hydrogen bonding interactions, thermal characteristics as well as in vitro dissolution studies conducted under sink conditions (pH 6.8). Particle size of OLZ in all formulations ranged between 42 and 58 μm. Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR), Differential Scanning Calorimetry (DSC) and Hot-Stage Microscopy (HSM) studies confirmed OLZ was well maintained in its crystalline state during the formulation process. In vitro dissolution studies showed immediate drug release from all formulation when compared to the drug alone. The greatest increase in in vitro dissolution rate was observed in formulations containing P188 most likely due to its enhanced hydrophilic and surfactant properties compared to the other agents used. Overall, this study successfully generated OLZ loaded SMD films with improved in vitro dissolution rates which is highly likely to result in improved oral bioavailability in vivo.
Keywords: Solid microcrystalline dispersion; Pharmaceutical film; Crystalline; Olanzapine; Polymer; PVP;
The effect of PEG molecular weights on the thermal stability and dissolution behaviors of griseofulvin-PEG crystalline inclusion complexes by Xiaotong Yang; Zhi Zhong; Yanbin Huang (51-60).
An optimized PEG molecular weight existed for the dissolution profile. This is the first study on the pharmaceutical profiles of drug-polymer crystalline inclusion complexes.Display OmittedCo-crystals formed between small molecular drugs and hydrophilic co-formers have shown great potential to optimize the dissolution profiles of drug substances. So far most of the co-formers used are small molecules. However, linear polymers are also able to form drug-polymer crystalline inclusion complexes (ICs). In contrast to the small molecular co-formers, molecular weight of the polymer co-formers can be easily changed without disrupting the IC crystal structure, and hence represents an interesting approach to tune the IC properties. In this study, we investigated the effect of PEG molecular weights on the thermal stability and dissolution behavior of Gris-PEG ICs. It was found that the thermal stability of Gris-PEG IC crystals first increased with PEG molecular weight, and then reached a plateau value, while an optimized PEG molecular weight existed for the dissolution profile. The experimental results were explained by the formation of two types of crystal defects during the IC growth in PEG melt: the void defects and the grain boundary defects. This is the first study on the pharmaceutical profiles of drug-polymer crystalline inclusion complexes.
Keywords: Inclusion complex; Pharmaceutical co-crystals; Insoluble drug;
One-step synthesis of iron oxide polypyrrole nanoparticles encapsulating ketoprofen as model of hydrophobic drug by Mohamed F. Attia; Nicolas Anton; Ikram Ullah Khan; Christophe A. Serra; Nadia Messaddeq; Anshuman Jakhmola; Raffaele Vecchione; Thierry Vandamme (61-70).
Display OmittedThis study reports a novel one-step synthesis of hybrid iron oxide/polypyrrole multifunctional nanoparticles encapsulating hydrophobic drug and decorated with polyethylene glycol. The overall process is based on the in situ chemical oxidative polymerization of pyrrole along with the reduction of ferric chloride (FeCl3) in the presence of ketoprofen as model drug and PEGylated surfactants. The final product is a nanocomposite composed of polypyrrole and a mixture of FeO/Fe2O3. Different concentrations of ketoprofen were encapsulated in the nanocomposite, and were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Encapsulation efficiency of the final product was measured by absorption, which can reach up to 98%. The release experiments confirmed complete drug release after about 3 h in PBS solution. Morphological characterization of the nanocomposites was performed by electron microscopy (scanning and transmission electron microscopy) which confirmed the spherical geometry and opaque nature of nanoparticles with average particle size well below 50 nm. The final product is multifunctional system, which could act both as a nanocarrier for drug molecules as well as a contrasting agent. Magnetic relaxometry studies confirmed their possible applications as potential contrast agent in the field of magnetic resonance imaging (MRI).
Keywords: Ketoprofen; Nanomedicine; Encapsulation; PEGylated shell; Drug delivery system; Polypyrrole; MRI contrasting agents;
Monitoring the recrystallisation of amorphous xylitol using Raman spectroscopy and wide-angle X-ray scattering by Emmi Palomäki; Patrik Ahvenainen; Henrik Ehlers; Kirsi Svedström; Simo Huotari; Jouko Yliruusi (71-82).
Display OmittedIn this paper we present a fast model system for monitoring the recrystallization of quench-cooled amorphous xylitol using Raman spectroscopy and wide-angle X-ray scattering. The use of these two methods enables comparison between surface and bulk crystallization. Non-ordered mesoporous silica micro-particles were added to the system in order to alter the rate of crystallization of the amorphous xylitol. Raman measurements showed that adding silica to the system increased the rate of surface crystallization, while X-ray measurements showed that the rate of bulk crystallization decreased. Using this model system it is possible to measure fast changes, which occur in minutes or within a few hours. Raman-spectroscopy and wide-angle X-ray scattering were found to be complementary techniques when assessing surface and bulk crystallization of amorphous xylitol.
Keywords: Amorphous; Crystallization; Raman spectrometry; Wide-angle X-ray scattering; Xylitol; Non-ordered mesoporous silica;
Cell uptake and intracellular fate of phospholipidic manganese-based nanoparticles by Manuela Costanzo; Lucia Scolaro; Gloria Berlier; Alessandro Marengo; Sabrina Grecchi; Carlo Zancanaro; Manuela Malatesta; Silvia Arpicco (83-91).
Display OmittedDuring the last decades, several studies have proposed manganese (Mn) complexes as alternative contrast agents for magnetic resonance imaging (MRI). With the nanotechnology surge in recent years, different types of Mn-based nanoparticles (Nps) have been developed. However, to design effective and safe administration procedures, preliminary studies on target cells, aimed at verifying their full biocompatibility and biodegradability, are mandatory.In this study, MnO containing-Nps encapsulated in a phospholipidic shell (PL-MnO Nps) were tested in cultured cells and flow cytometry; confocal and transmission electron microscopy were combined to understand the Nps uptake mechanism, intracellular distribution and degradation pathways, as well as possible organelle alterations.The results demonstrated that PL-MnO Nps undergo rapid and massive cell internalization, and persist free in the cytoplasm before undergoing lysosomal degradation without being cytotoxic or inducing subcellular damage. Based on the results with this cell model in vitro, PL-MnO Nps thus proved to be suitably biocompatible, and may be envisaged as very promising tools for therapeutic and diagnostic applications, as drug carriers or contrast agent for MRI.
Keywords: Manganese; Nanoparticles; Cell uptake; Fluorescence microscopy; Transmission electron microscopy;
Development of antimicrobial and scar preventive chitosan hydrogel wound dressings by Sadiya Anjum; Abha Arora; M.S. Alam; Bhuvanesh Gupta (92-101).
Display OmittedAntimicrobial and scar preventive wound dressings were developed by coating a blend of chitosan (CS), polyethylene glycol (PEG) and polyvinyl pyrolidone (PVP) on the cotton fabric and subsequent freeze drying. The miscibility of blend systems and functional group interaction were investigated by attenuated total reflectance-infra red spectroscopy. The scanning electron microscopy of the coated fabric revealed porous structure. The porosity of the material was 54–70% and the pore size was in the range of 75-120 μm depending on the blend composition. The air permeability diminished as the PVP content increased. The water vapour transmission rate was in the range of 2000–3500 g/m2day which may offer to be proper material for the wound dressing with moderate exudate absorption. Tetracycline hydrochloride was used as model drug within the hydrogel matrix. The cumulative release of drug was found to be ∼80% of the total loading after ∼48 h. The drug loaded dressings showed good antimicrobial nature against both gram positive and gram negative bacteria. In vivo wound healing and tissue compatibility studies were carried out over a period of 21 days on full-thickness skin wounds created on male Wistar rats. Fast healing was observed in drug loaded dressing treated wounds with minimum scarring, as compared to the other groups. These results suggest that drug loaded dressing could provide scar preventive wound healing.
Keywords: Chitosan; Polyethylene glycol; Polyvinyl pyrolidine; Tetracycline hydrochloride; Wound dressing; Scar preventive;
Impact of lipases on the protective effect of SEDDS for incorporated peptide drugs towards intestinal peptidases by Gintare Leonaviciute; Ožbej Zupančič; Felix Prüfert; Julia Rohrer; Andreas Bernkop-Schnürch (102-108).
Summary on properties of SEDDS to protect peptide drug towards enzymatic hydrolysis and to bring their higher concentration to the absorption site in the digestive tract. (Poly)peptide drug (♦).Display OmittedThe aim of this study is the development of self-emulsifying drug delivery systems (SEDDS) differing in amounts of ester substructures and to evaluate their stability in presence of pancreatic lipase and protective effect against luminal enzymatic metabolism using leuprorelin as model peptide drug.Hydrophobic leuprolide oleate was incorporated into three different SEDDS formulations and their stability towards pancreatic lipases was investigated utilizing a dynamic in vitro digestion model. Protective effect of SEDDS in respect to peptide drug stability against proteolytic enzymes, trypsin and α-chymotrypsin, was determined via HPLC.Results of in vitro digestion demonstrated that 80% of SEDDS containing the highest amount of ester linkages was degraded within 60 min. In comparison to that, SEDDS without ester bonds showed no degradation. With increasing oil droplets hydrolysis the remaining amount of peptide encapsulated into formulation decreased. Furthermore, after 180 min incubation with trypsin up to 33.5% and with α-chymotrypsin up to 60.5% of leuprolide oleate was intact while leuprorelin acetate aqueous solution was completely metabolized by trypsin within 120 min and by α-chymotrypsin within 5 min. Protective effect in environment containing lipases was lower due to oil phase degradation, however, the amount of peptide in ester-free SEDDS was remarkably higher compared to SEDDS susceptible to lipases.The present study revealed that SEDDS stable towards hydrolysis is able to exhibit a protective effect for oral peptide delivery.
Keywords: α-Chymotrypsin; Digestion; Pancreatic lipase; Peptide; Self-nanoemulsifying system; Trypsin;
Crystal form control and particle size control of RG3487, a nicotinic α7 receptor partial agonist by Shanming Kuang; Pingsheng Zhang; Eric Z. Dong; Geremia Jennings; Baoshu Zhao; Michael Pierce (109-122).
This paper describes the crystal form control and particle size control of a drug candidate, RG3487. Based on polymorph screen results and form stability investigation, the crystal form control was achieved by appropriate crystallization solvent selection which consistently produced the desired solid form. The particle size control was successfully accomplished by tuning key crystallization parameters, including HCl addition temperature, agitation rate, MTBE addition time and hold times. As a result, three batches of drug substances in 500 g scale with the right crystal form and intentionally different particle sizes were produced for downstream formulation development.Display OmittedThis paper describes solid form control and particle size control of RG3487, a nicotinic receptor partial agonist. Four crystal forms were identified by polymorph screen under ∼100 varying conditions. Form A and Form B are anhydrates, while Forms C and D are solvates. Forms A, which is enantiotropically related to Form B, is the more thermodynamically stable form under ambient conditions and the desired form selected for clinical development. The crystal form control of Form A was achieved by crystallization solvent selection which consistently produced the desired form. Several process parameters impacting particle size of Form A in the final crystallization step were identified and investigated through both online and offline particle size measurement. The investigation results were utilized to control crystallization processes which successfully produced Form A with different particle size in 500 g scale.
Keywords: RG3487; Polymorph screen; Crystal form control; Particle size control; Crystallization; Form stability;
Do surface-based match solution-based techniques? The case of drug-liposome interaction by Giuseppe Ermondi; Giulia Caron (123-127).
Display OmittedThe aim of the study is to check if the information about drug/liposome interactions provided by Surface Plasmon Resonance (SPR) is comparable with that provided by potentiometry in which liposomes are not immobilized on a solid support. To reach our aim we apply QSPR and BR analysis to data extracted from the literature and carefully inspected for their reliability. Results show that log KD (SPR) is governed by a different balance of intermolecular interactions than log Dlip (potentiometry).
Keywords: Block relevance analysis; Lipophilicity; Liposomes; Potentiometry; Quantitative Structure-Property Relationship (QSPR); Surface Plasmon Resonance (SPR);
Optimization and modeling of the remote loading of luciferin into liposomes by Anders Højgaard Hansen; Michael A. Lomholt; Per Lyngs Hansen; Ole G. Mouritsen; Ahmad Arouri (128-134).
Display OmittedWe carried out a mechanistic study to characterize and optimize the remote loading of luciferin into preformed liposomes of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPC/DPPG) 7:3 mixtures. The influence of the loading agent (acetate, propionate, butyrate), the metal counterion (Na+, K+, Ca+2, Mg+2), and the initial extra-liposomal amount of luciferin ( n L a d d ) on the luciferin Loading Efficiency (LE%) and luciferin-to-lipid weight ratio, i.e., Loading Capacity (LC), in the final formulation was determined. In addition, the effect of the loading process on the colloidal stability and phase behavior of the liposomes was monitored. Based on our experimental results, a theoretical model was developed to describe the course of luciferin remote loading. It was found that the highest luciferin loading was obtained with magnesium acetate. The use of longer aliphatic carboxylates or inorganic proton donors pronouncedly reduced luciferin loading, whereas the effect of the counterion was modest. The remote-loading process barely affected the colloidal stability and drug retention of the liposomes, albeit with moderate luciferin-induced membrane perturbations. The correlation between luciferin loading, expressed as LE% and LC, and n L a d d was established, and under our conditions the maximum LC was attained using an n L a d d of around 2.6 μmol. Higher amounts of luciferin tend to pronouncedly perturb the liposome stability and luciferin retention. Our theoretical model furnishes a fair quantitative description of the correlation between n L a d d and luciferin loading, and a membrane permeability coefficient for uncharged luciferin of 1 × 10−8 cm/s could be determined. We believe that our study will prove very useful to optimize the remote-loading strategies of moderately polar carboxylic acid drugs in general.
Keywords: Liposome; Luciferin remote loading; Carboxylate gradient; Drug encapsulation; Phospholipase A2 enzyme; Modeling; Diffusion;
Corrigendum to “Macroporous natural capsules extracted from Phoenix dactylifera L. spore and their application in oral drugs delivery” [Int. J. Pharm. 504 (2016) 39–47] by Saad M. Alshehri; Hamad A. Al-Lohedan; Eida Al-Farraj; Norah Alhokbany; Anis Ahmad Chaudhary; Tansir Ahamad (135).