International Journal of Pharmaceutics (v.507, #1-2)

Display OmittedRecently, electrospun nanofibrous scaffolds are vastly taken into consideration in the bone tissue engineering due to mimicking the natural structure of native tissue. In our study, surface features of nanofibers were modified through simultaneous electrospining of the synthetic and natural polymers using poly l-lactide (PLLA) and gelatin to fabricate the hybrid scaffold (PLLA/gelatin). Then, hydroxyapatite nanoparticles (nHA) were loaded in electrospun PLLA nanofibers (PLLA,nHA/gelatin) and also dexamethasone (DEX) was incorporated in these fibers (PLLA,nHA,DEX/gelatin) in the second experiment. Fabricated nanofibrous composite scaffolds were characterized via SEM, FTIR spectroscopy, contact angle, tensile strength measurements, DEX release profile and MTT assay. After seeding adipose derived mesenchymal stem cells, osteoinductivity and osteoconductivity of fabricated scaffolds were analyzed using common osteogenic markers such as alkaline phosphatase activity, calcium depositions and gene expression. These results confirmed that all properties of nanofibers were improved by modifications. Moreover, osteogenic differentiation of stem cells increased in PLLA,nHA/gelatin group in comparison with PLLA/gelatin. The sustained release of DEX was obtained from PLLA,nHA,DEX/gelatin which subsequently led to more osteogenic differentiation. Taken together, PLLA,nHA,DEX/gelatin showed significant potential to support the stem cell proliferation and ostogenic differentiation, and can be a good candidates for tissue engineering and regenerative medicine applications.
Keywords: Tissue engineering; Electrospinning; Gelatin; Nano-hydroxyapatite; Dexamethasone; Mesenchymal stem cells;

Skin penetration and dermal tolerability of acrylic nanocapsules: Influence of the surface charge and a chitosan gel used as vehicle by R.V. Contri; L.A. Fiel; N. Alnasif; A.R. Pohlmann; S.S. Guterres; M. Schäfer-Korting (12-20).
Display OmittedFor an improved understanding of the relevant particle features for cutaneous use, we studied the effect of the surface charge of acrylic nanocapsules (around 150 nm) and the effect of a chitosan gel vehicle on the particle penetration into normal and stripped human skin ex vivo as well as local tolerability (cytotoxicity and irritancy). Rhodamin-tagged nanocapsules penetrated and remained in the stratum corneum. Penetration of cationic nanocapsules exceeded the penetration of anionic nanocapsules. When applied on stripped skin, however, the fluorescence was also recorded in the viable epidermis and dermis. Cationic surface charge and embedding the particles into chitosan gel favored access to deeper skin. Keratinocytes took up the nanocapsules rapidly. Cytotoxicity (viability < 80%), following exposure for ≥24 h, appears to be due to the surfactant polysorbate 80, used for nanocapsuleś stabilization. Uptake by fibroblasts was low and no cytotoxicity was observed. No irritant reactions were detected in the HET-CAM test. In conclusion, the surface charge and chitosan vehicle, as well as the skin barrier integrity, influence the skin penetration of acrylic nanocapsules. Particle localization in the intact stratum corneum of normal skin and good tolerability make the nanocapsules candidates for topical use on the skin, provided that the polymer wall allows the release of the active encapsulated substance.
Keywords: Chitosan; Cytotoxicity; Irritancy; Nanocapsules; Polymer; Skin penetration;

Cyclodextrin-based telmisartan ophthalmic suspension: Formulation development for water-insoluble drugs by Chutimon Muankaew; Phatsawee Jansook; Hákon Hrafn Sigurđsson; Thorsteinn Loftsson (21-31).
Display OmittedIn this study, cyclodextrin-based aqueous eye drop suspension of the water insoluble drug telmisartan was developed. Formation of a drug/γ-cyclodextrin complex was enabled by preventing formation of a poorly water-soluble zwitterion using a volatile base that was removed upon drying of the complex powder. Hydroxypropyl methylcellulose was shown to have the overall best effect, stabilizing the complexes without hampering the drug release from the formulation. Two strategies for preparing cyclodextrin-based aqueous eye drop suspensions of telmisartan were investigated, one where hydroxypropyl methylcellulose was added to the medium during preparation of the drug/γ-cyclodextrin complex powder (ternary complex) and the other where hydroxypropyl methylcellulose was added to the complex powder after preparation of the complex (binary complex). The complexation was characterized by DSC, FT-IR and 1H NMR and the eye drop suspensions formed were examined regarding their stability and in vitro mucoadhesion property. The ternary complex exhibited inferior mucoadhesive property compared to the binary complex. However, the ternary complex was more stable as no notable change in particle size and particle size distribution was observed during storage at 4 °C over 6 months (p  < 0.05) with the mean particle size determined between 2.0 and 2.5 μm.
Keywords: Telmisartan; γ-cyclodextrin; Ophthalmic suspension; Microparticles; Lyophilization; Stabilize;

Characteristics and cytotoxicity of folate-modified curcumin-loaded PLA-PEG micellar nano systems with various PLA:PEG ratios by Quoc Thong Phan; Mai Huong Le; Thi Thu Huong Le; Thi Hong Ha Tran; Phuc Nguyen Xuan; Phuong Thu Ha (32-40).
Display OmittedTargeting delivery system use natural drugs for tumor cells is an appealing platform help to reduce the side effects and enhance the therapeutic effects of the drug. In this study, we synthesized curcumin (Cur) loaded (D, L Poly lactic – Poly ethylenglycol) micelle (Cur/PLA-PEG) with the ratio of PLA/PEG of 3:1 2:1 1:1 1:2 and 1:3 (w/w) and another micelle modified by folate (Cur/PLA-PEG-Fol) for targeting cancer therapy. The PLA-PEG copolymer was synthesized by ring opening polymerization method. After loading onto the micelle, solubility of Cur increased from 0.38 to 0.73 mg ml−1. The average size of prepared Cur/PLA-PEG micelles was from 60 to 69 nm (corresponding to the ratio difference of PLA/PEG) and the drug encapsulating efficiency was from 48.8 to 91.3%. Compared with the Cur/PLA-PEG micelles, the size of Cur/PLA-PEG-Fol micelles were from 80 to 86 nm and showed better in vitro cellular uptake and cytotoxicity towards HepG2 cells. The cytotoxicity of the NPs however depends much on the PEG component. The results demonstrated that Folate-modified micelles could serve as a potential nano carrier to improve solubility, anti-cancer activity of Cur and targeting ability of the system.
Keywords: Curcumin (Cur); PLA-PEG copolymer; PLA-PEG/Cur; PLA-PEG/Cur/Fol;

Ca3(PO4)2 precipitated layering of an in situ hybridized PVA/Ca2O4Si nanofibrous antibacterial wound dressing by Mostafa Mabrouk; Yahya E. Choonara; Thashree Marimuthu; Pradeep Kumar; Lisa C. du Toit; Sandy van Vuuren; Viness Pillay (41-49).
Display OmittedThe aim of this study was to develop an in situ hybridized poly(vinyl alcohol)/calcium silicate (PVA/Ca2OSi) nanofibrous antibacterial wound dressing with calcium phosphate [Ca3(PO4)2] surface precipitation for enhanced bioactivity. This was achieved by hybridizing the antibacterial ions Zn2+ and/or Ag+ in a Ca2O4Si composite. The hybridization effect on the thermal behavior, physicochemical, morphological, and physicomechanical properties of the nanofibers was studied using Differential Scanning calorimetric (DSC), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Textural Analysis, respectively. In vitro bioactivity, biodegradation and pH variations of the nanofiber composite were evaluated in Simulated Body Fluid (SBF). The antibacterial activity was assessed against Staphylococcus aureus and Pseudomonas aeruginosa. Hybridization of Zn2+ and/or Ag+ into the PVA/Ca2O4Si nanofiber composite was confirmed by DSC, XRD and FTIR. The thickness of the nanofibers was dependent on the presence of Zn2+ and Ag+ as confirmed by SEM. The nanofibers displayed enhanced tensile strength (19–115.73 MPa) compared to native PVA. Zn2+ and/or Ag+ hybridized nanofibers showed relatively enhanced in vitro bioactivity, biodegradation (90%) and antibacterial activity compared with the native PVA/Ca2O4Si nanofiber composite. Results of this study has shown that the PVA/Ca2O4Si composite hybridized with both Zn2+ and Ag+ may be promising as an antibacterial wound dressing with a nanofibrous archetype with enhanced bioactivity.
Keywords: Antibacterial wound dressing; Bioactivity; Polyvinyl alcohol/calcium silicate nanofibers; Zn2+; Ag+; Calcium phosphate precipitation;

Dual-pH responsive micelle platform for co-delivery of axitinib and doxorubicin by Xiuli Xu; Lian Li; Zhou Zhou; Wei Sun; Yuan Huang (50-60).
Display OmittedIllustration of dual-pH responsive micellar platform for co-delivery of axitinib (AXI) and doxorubicin (DOX) based on HPMA coplymers.While the complicated pathogenesis of cancer results in limited therapeutic efficacy of current mono-drug treatment, combination therapy by multiple drugs is becoming increasingly attractive due to the decreased side effects and synergistic anti-cancer activities. The recently emerging modality is the co-delivery of traditional chemotherapeutics and anti-angiogenesis agents. Although nanocarriers are frequently utilized for the co-delivery of different drugs, there are still concerns regarding their implementations. Most of the nanocarriers cannot release drugs separately into their different targeted sites of action. Therefore, we have developed a micellar platform for the co-delivery of an antiangiogenesis agent, axitinib (AXI) and a DNA intercalator, doxorubicin (DOX). Our results showed that this cross-linked micelle (DA-CM) could release AXI and DOX in tumor extracellular environment and intracellular lysosome compartments, respectively, in response to the dual pH stimulus. Notably, DA-CM exhibited remarkably improved tumor accumulation, cell internalization, tumor spheroids penetration and cytotoxicity. Ultimately, DA-CM reduced the number of immature vessels within xenograft tumors, demonstrating an effective antiangiogenesis effect. Meanwhile, they inhibited tumor growth by 88%. Our co-delivery micellar system with the dual-pH responsive feature might hold great promises for the combinatory cancer therapy.
Keywords: pH-responsive; Combination therapy; Synergistic effect; Antiangiogenesis; HPMA micelle;

Display OmittedOverexpression of P-glycoprotein (P-gp) efflux transporter in glioma cells thwarts the build-up of therapeutic concentration of drugs usually resulting into poor therapeutic outcome. To surmount aforesaid challenge, Imatinib (IMM) loaded Poly-lactide-co-glycolic acid nanoparticles (IMM-PLGA-NPs) were developed and optimized by Box Behnken Design as a new treatment stratagem in malignant glioma. Optimized NPs were functionalized with Pluronic® P84, P-gp inhibitor (IMM-PLGA-P84-NPs) which showed size, PDI, zeta potential, drug loading, 182.63 ± 13.56 nm, 0.196 ± 0.021, −15.2 ± 1.49 mV, 40.63 ± 2.04 μg/mg, respectively. Intracellular uptake study conducted on A172, U251MG and C6 glioma cells demonstrated significantly high uptake of IMM through NPs when compared with IMM solution (IMM-S), p < 0.001. IMM-PLGA-P84-NPs showed better uptake in P-gp expressing cell line (U251MG and C6) while uncoated NPs showed higher uptake in non-P-gp expressing cell line (A-172). Cytotoxicity studies demonstrated significantly low IC50 for both IMM-PLGA-NPs and IMM-PLGA-P84-NPs when compared with IC50 of IMM-S. IMM-PLGA-P84-NPs showed a significantly low IC50 against P-gp overexpressing cell lines when compared with IC50 of IMM-PLGA-NPs. In contrary, IMM-PLGA-NPs showed lower IC50 against non P-gp expressing cell line. This study demonstrated the feasibility of targeting surface decorated NPs to multidrug resistant gliomas. However, to address its clinical utility extensive in vivo studies are required.
Keywords: Imatinib mesylate; PLGA; Pluronic® P84; Glioblastoma; P-glycoprotein;

In-vivo dermal pharmacokinetics, efficacy, and safety of skin targeting nanoparticles for corticosteroid treatment of atopic dermatitis by Muhammad Irfan Siddique; Haliza Katas; Mohd Cairul Iqbal Mohd Amin; Shiow-Fern Ng; Mohd Hanif Zulfakar; Adawiyah Jamil (72-82).
Display OmittedThe objective of this study was to investigate the in-vivo behavior of topically applied cationic polymeric chitosan nanoparticles (CSNPs) loaded with anti-inflammatory (hydrocortisone, HC) and antimicrobial (hydroxytyrosol, HT) drugs, to elucidate their skin targeting potential for the treatment of atopic dermatitis (AD). Compared to the commercial formulation, the HC-HT loaded CSNPs showed significantly improved drug penetration into the epidermal and dermal layers of albino Wistar rat skin without saturation. Dermal pharmacokinetic of CSNPs with a size of 228.5 ± 7 nm and +39 ± 5 mV charges revealed that they penetrated 2.46-fold deeper than the commercial formulation did, and had greater affinity at the skin target site without spreading to the surrounding tissues, thereby providing substantial safety benefits. In repeated dermal application toxicity studies, the HC-HT CSNPs showed no evidence of toxicity compared to the commercial formulation, which induced skin atrophy and higher liver enzyme levels. In conclusion, the positively charged HC-HT CSNP formulation exhibited promising local delivery and virtually no treatment-related toxicities, suggesting it may be an efficient and viable alternative for commercially available AD treatments.
Keywords: Polymeric nanoparticles; Skin disease; Chitosan; Topical glucocorticoids; Antimicrobial activity; Dermal pharmacokinetics; Safety;

Toward predicting tensile strength of pharmaceutical tablets by ultrasound measurement in continuous manufacturing by Sonia M. Razavi; Gerardo Callegari; German Drazer; Alberto M. Cuitiño (83-89).
Display OmittedAn ultrasound measurement system was employed as a non-destructive method to evaluate its reliability in predicting the tensile strength of tablets and investigate the benefits of incorporating it in a continuous line, manufacturing solid dosage forms. Tablets containing lactose, acetaminophen, and magnesium stearate were manufactured continuously and in batches. The effect of two processing parameters, compaction force and level of shear strain were examined. Young's modulus and tensile strength of tablets were obtained by ultrasound and diametrical mechanical testing, respectively. It was found that as the blend was exposed to increasing levels of shear strain, the speed of sound in the tablets decreased and the tablets became both softer and mechanically weaker. Moreover, the results indicate that two separate tablet material properties (e.g., relative density and Young's modulus) are necessary in order to predict tensile strength. A strategy for hardness prediction is proposed that uses the existing models for Young's modulus and tensile strength of porous materials. Ultrasound testing was found to be very sensitive in differentiating tablets with similar formulation but produced under different processing conditions (e.g., different level of shear strain), thus, providing a fast, and non-destructive method for hardness prediction that could be incorporated to a continuous manufacturing process.
Keywords: Tensile strength; Young's modulus; Ultrasound; Mechanical properties;

Transdermal permeation of drugs with differing lipophilicity: Effect of penetration enhancer camphor by Feng Xie; Jia-ke Chai; Quan Hu; Yong-hui Yu; Li Ma; Ling-ying Liu; Xu-long Zhang; Bai-ling Li; Dong-hai Zhang (90-101).
Display OmittedThe aim of the present study was to investigate the potential application of (+)-camphor as a penetration enhancer for the transdermal delivery of drugs with differing lipophilicity. The skin irritation of camphor was evaluated by in vitro cytotoxicity assays and in vivo transdermal water loss (TEWL) measurements. A series of model drugs with a wide span of lipophilicity (log  P value ranging from 3.80 to −0.95), namely indometacin, lidocaine, aspirin, antipyrine, tegafur and 5-fluorouracil, were tested using in vitro transdermal permeation experiments to assess the penetration-enhancing profile of camphor. Meanwhile, the in vivo skin microdialysis was carried out to further investigate the enhancing effect of camphor on the lipophilic and hydrophilic model drugs (i.e. lidocaine and tegafur). SC (stratum corneum)/vehicle partition coefficient and Fourier transform infrared spectroscopy (FTIR) were performed to probe the regulation action of camphor in the skin permeability barrier. It was found that camphor produced a relatively low skin irritation, compared with the frequently-used and standard penetration enhancer laurocapram. In vitro skin permeation studies showed that camphor could significantly facilitate the transdermal absorption of model drugs with differing lipophilicity, and the penetration-enhancing activities were in a parabola curve going downwards with the drug log  P values, which displayed the optimal penetration-enhancing efficiency for the weak lipophilic or hydrophilic drugs (an estimated log  P value of 0). In vivo skin microdialysis showed that camphor had a similar penetration behavior on transdermal absorption of model drugs. Meanwhile, the partition of lipophilic drugs into SC was increased after treatment with camphor, and camphor also produced a shift of CH2 vibration of SC lipid to higher wavenumbers and decreased the peak area of the CH2 vibration, probably resulting in the alteration of the skin permeability barrier. This suggests that camphor might be a safe and effective penetration enhancer for transdermal drug delivery.
Keywords: Camphor; Penetration enhancer; Transdermal permeation; Microdialysis; ATR-FTIR;

Display OmittedDevelopment of an oral docetaxel formulation has been hindered mainly due to its poor solubility and oral bioavailability. The aim of this study was to develop poloxamer F68/P85-based solid dispersions (SDs) for the oral delivery of docetaxel and investigate their in vivo pharmacokinetic impacts on the systemic absorption of docetaxel given orally, in comparison with a SD based on F68 alone. The F68 and/or P85-based docetaxel SDs were prepared with varying the contents of poloxamers and then evaluated in terms of morphology, crystallinity, solubility, dissolution, permeation across rat intestinal segments, and oral pharmacokinetics in rats. As a result, the SDs successfully changed the crystalline properties of docetaxel and enhanced the drug solubility and dissolution. The SD prepared with F68 alone significantly enhanced the dissolution but not intestinal permeation of docetaxel, leading to only limited enhancement of oral bioavailability (1.39-fold increase). Notably, however, the F68/P85-based SD significantly enhanced both the dissolution and intestinal permeation of docetaxel, achieving a markedly improved oral bioavailability (2.97-fold increase). Therefore, the present results suggest that the intestinal permeation factor should be taken into account when designing SD formulations for the oral delivery of BCS class IV drugs including docetaxel, and that P85 could serve as a potential formulation excipient for enhancing the intestinal permeation of docetaxel.
Keywords: Docetaxel; Lutrol F68; Pluronic P85; Solid dispersion; Freeze-drying method; Oral bioavailability;