Nanostructured lipid carriers loaded with Halobetasol propionate for topical treatment of inflammation: Development, characterization, biopharmaceutical behavior and therapeutic efficacy of gel dosage forms.

The aim of this research was the development and characterization of three gel dosage forms of Halobetasol propionate loaded lipid nanoparticles (HB-NLC) for the treatment of inflammatory skin diseases. A Pluronic gel (Pl-HB-NLC), a Carbopol gel (Cb-HB-NLC) and a Cremigel (Cg-HB-NLC), were characterized for stability, swelling, degradation, porosity and rheology. The biopharmaceutical behavior of in vitro release and ex vivo permeation, along with microbiological stability were also evaluated. Tolerance and therapeutic efficacy were determined in vivo. The gels proved to have eudermic pH and to be effective to improve HB-NLC stability for more than 6 months. In vitro drug release profiles were adjusted to a first order (Pl-HB-NLC, Cg-HB-NLC) and hyperbola (Cb-HB-NLC) kinetic models, revealing sustained drug release. Ex vivo biopharmaceutical behavior showed slow drug penetration through skin, delaying the drug entrance into systemic circulation. The formulations were effective in reducing inflammation with a lower drug dose in comparison with existing treatments, obtaining the fastest effect when using Pl-HB-NLC. After application of the formulations in volunteers, no irritation, redness or edema reactions were detected, plus, an enhancement of the biomechanical properties of the skin was evidenciated. Therefore, the results indicate that these formulations are a suitable alternative to current treatments.

Development of Halobetasol-loaded nanostructured lipid carrier for dermal administration: Optimization, physicochemical and biopharmaceutical behavior, and therapeutic efficacy.

Halobetasol propionate (HB) is considered a super potent drug in the group of topical corticosteroids. HB has anti-inflammatory activity, vasoconstriction properties, and due to its high skin penetration, it can cause systemic side effects. To improve its characteristics, enhance topical effectiveness and reduce penetration to systemic circulation, a study to optimize and characterize a HB-loaded lipid nanocarrier (HB-NLC) has been made by high-pressure homogenization method. The formulation is composed by HB, surfactant, glyceryl distearate and capric glycerides. The optimized HB-NLC containing 0.01% of HB and 3% of total lipid shows an average size below 200 nm with a polydispersity index ≪0.2 and an encapsulation efficiency ≫90%. The in vitro and in vivo tests indicate that the HB-NLC is not toxic, is well tolerated and has an anti-inflammatory effect because they decrease the production of Interleukins in keratinocytes and monocytes. HB-NLC is considered an alternative treatment for skin inflammatory disorders.

Current Research Therapeutic Strategies for Alzheimer's Disease Treatment.

Alzheimer's disease (AD) currently presents one of the biggest healthcare issues in the developed countries. There is no effective treatment capable of slowing down disease progression. In recent years the main focus of research on novel pharmacotherapies was based on the amyloidogenic hypothesis of AD, which posits that the beta amyloid (Aß) peptide is chiefly responsible for cognitive impairment and neuronal death. The goal of such treatments is (a) to reduce Aß production through the inhibition of ß and γ secretase enzymes and (b) to promote dissolution of existing cerebral Aß plaques. However, this approach has proven to be only modestly effective. Recent studies suggest an alternative strategy centred on the inhibition of the downstream Aß signalling, particularly at the synapse. Aß oligomers may cause aberrant N-methyl-D-aspartate receptor (NMDAR) activation postsynaptically by forming complexes with the cell-surface prion protein (PrPC). PrPC is enriched at the neuronal postsynaptic density, where it interacts with Fyn tyrosine kinase. Fyn activation occurs when Aß is bound to PrPC-Fyn complex. Fyn causes tyrosine phosphorylation of the NR2B subunit of metabotropic glutamate receptor 5 (mGluR5). Fyn kinase blockers masitinib and saracatinib have proven to be efficacious in treating AD symptoms in experimental mouse models of the disease.

Effect of E-beam treatment on the chemistry and on the antioxidant activity of lycopene from dry tomato peel and tomato powder.

Tomato powder (TP) and dry tomato peel (DTP) have been previously used in our laboratory as a source of lycopene to manufacture meat products ready-to-eat (RTE) submitted to E-beam irradiation with good technological and sensory results. Present work describes the studies performed in order to investigate the effect of radiation on chemical changes and antioxidant properties of lycopene. DTP and TP were irradiated (4 kGy). Changes on lycopene were analyzed by HPLC; inhibition of reactive oxygen species (ROS), possible modulation of mitogen-activated protein kinases (MAPK) cascade, nuclear factor κ-light-chain-enhancer of activated B cells (NP-κB) activation and expression of proteins involved in oxidation stress were analyzed in RAT-1 fibroblasts cell culture. Radiation reduced the content of all-E-lycopene and increased (Z)-lycopene, lycopene isomerization, and degradation being higher in DTP than in TP. E-Beam treatment increased the antioxidant ability of both DTP and TP in inhibiting spontaneous and H2O2-induced oxidative stress in cultured fibroblasts. Antioxidant activity was higher in DTP than in TP samples.

Flurbiprofen PLGA-PEG nanospheres: role of hydroxy-ß-cyclodextrin on ex vivo human skin permeation and in vivo topical anti-inflammatory efficacy.

In this study, flurbiprofen (FB) loaded poly(d,l-lactide-co-glycolide) (PLGA) and PLGA with poly(ethylene glycol) (PLGA-PEG) nanospheres (NSs) with and without hydroxypropyl-ß-cyclodextrin (HPßCD) were developed as skin controlled delivery systems. X-ray diffraction was used to determine the physical state of the entrapped drug. Results showed that the drug in PLGA NSs was present in the form of a molecular dispersion (dissolved state) in the polymers, whereas in PLGA-PEG NSs, the drug was present in both molecular dispersion and crystalline forms. Furthermore, HPßCD provided solubilization of the free FB present on the surface of the PLGA-PEG NSs and a complete amorphosization of the drug was obtained. Optical analyses using TurbiscanLab(®) demonstrated that HPßCD provided an efficient steric stability of the NSs, preventing particle aggregation. The ex vivo permeation profiles of the NSs and conventional FB solution were evaluated using human skin. Results demonstrated that only PLGA-PEG NSs showed slight permeation improvement. However, after 24h, the FB retained in the skin was about 9-fold higher with NSs compared with the control solution, attributed to the reservoir effect of NSs acting as a depot, sustaining the drug and limiting its systemic absorption. In vivo performance of NSs was evaluated by assessing anti-inflammatory efficacy in TPA-induced mouse ear edema. Topically applied NSs significantly decreased in vivo inflammation compared to the control solution and the anti-inflammatory efficacy of HPßCD NSs was stronger than NSs without HPßCD. In vivo skin irritation evaluated by the in vivo Draize test showed no irritation of the formulations tested.

Role of hydroxypropyl-ß-cyclodextrin on freeze-dried and gamma-irradiated PLGA and PLGA-PEG diblock copolymer nanospheres for ophthalmic flurbiprofen delivery.

Poly(D,L-lactide-co-glycolide) and poly(D,L-lactide-co-glycolide) with poly(ethylene glycol) nanospheres (NSs) incorporating flurbiprofen (FB) were freeze-dried with several cryoprotective agents and sterilized by γ-irradiation. Only when 5.0% (w/v) hydroxypropyl-ß-cyclodextrin (HPßCD) was used, a complete resuspension by manual shaking and almost identical particle size of the NSs was obtained after freeze-drying. In vitro drug release and ex vivo corneal permeation of NSs with and without HPßCD were evaluated. The presence of HPßCD resulted in a reduction of burst effect, providing a more sustained release of the drug. A significant decrease in the FB transcorneal permeation of NSs containing HPßCD was obtained, related to the slower diffusion of FB observed in the in vitro results. The uptake mechanism of the NSs was examined by confocal microscopy, suggesting that NSs penetrate corneal epithelium through a transcellular pathway. Ocular tolerance was assessed in vitro and in vivo by the Eytex™ and Draize test, respectively. Long-term stability studies revealed that γ-irradiated NSs stored as freeze-dried powders maintained their initial characteristics. Stability studies of the resuspended NSs after 3 months of storage in the aqueous form showed that NSs were stable at 4°C, while formulations stored at 25°C and 40°C increased their initial particle size.

Improved and safe transcorneal delivery of flurbiprofen by NLC and NLC-based hydrogels.

Flurbiprofen (FB)-loaded nanostructured lipid carriers (NLCs) based on Compritol®888 ATO (C888; FB-C888NLC) were developed for anti-inflammatory ocular therapy. NLCs prepared by high-pressure homogenization technique following a factorial design had low particle size (<199 nm), high entrapment efficiency (∼90%), and long-term physical stability. Previously optimized NLCs based on stearic acid (SA; FB-SANLC) were prepared for comparison studies. Both formulations were dispersed in freshly prepared carbomer hydrogel (HG) to check the suitability of semisolid-based NLC HGs to enhance the corneal residence time. FB-C888NLC remained in the nanometric range, whereas FB-SANLC suffered an increase in particle size up to 5 µm after incorporation. Consequently, modifications in the crystalline lattice structure were observed for FB-SANLC-enriched HG (HG_FB-SANLC) by X-ray diffractometry. Both HG formulations showed plastic and low or no thixotropic properties, making them suitable for ocular application while maintaining its predominant elastic component as an indicator of good physicochemical stability. Formulations depicted sustained FB release. Ex vivo permeation analysis in isolated rabbit cornea revealed enhanced transcorneal drug permeation from the systems. In vivo ocular tolerance was confirmed by the Draize test. Therefore, NLC are promising and effective systems for ocular delivery of FB.

Pyrazolo[3,4-c]pyridazines as novel and selective inhibitors of cyclin-dependent kinases.

Pyrazolopyridazine 1a was identified in a high-throughput screening carried out by BASF Bioresearch Corp. (Worcester, MA) as a potent inhibitor of CDK1/cyclin B and shown to have selectivity for the CDK family. Analogues of the lead compound have been synthesized and their antitumor activities have been tested. A molecular model of the complex between the lead compound and the CDK2 ATP binding site has been built using a combination of conformational search and automated docking techniques. The stability of the resulting complex has been assessed by molecular dynamics simulations and the experimental results obtained for the synthesized analogues have been rationalized on the basis of the proposed binding mode for compound 1a. As a result of the SAR study, monofuryl 1o has been synthesized and is one of the most active compounds against CDK1 of this series.

Synthesis and biological evaluation of analogues of butyrolactone I and molecular model of its interaction with CDK2.

A series of analogues of butyrolactone I, a natural product isolated from Aspergillus terreus that selectively inhibits the CDK2 and CDK1 kinases and that has been found to exhibit an interesting antiproliferative activity, have been synthesized. Its antitumor activity has been tested. Molecular models of the complex between butyrolactone I and the CDK2 active site have been built using a combination of conformational search and automated docking techniques. The stability of the resulting complexes has been assessed by molecular dynamics simulations and the experimental results obtained for the synthesized analogues are rationalized based on the molecular models.

Structure-based design of cyclooxygenase-2 selectivity into ketoprofen.

We have recently described how to achieve COX-2 selectivity from the non-selective inhibitor indomethacin (1) using a combination of a pharmacophore and computer 3-D models based on the known X-ray crystal structures of cyclooxygenases. In the present study we have focused on the design of COX-2 selective analogues of the NSAID ketoprofen (2). The design is similarly based on the combined use of the previous pharmacophore together with traditional medicinal chemistry techniques motivated by the comparative modeling of the 3-D structures of 2 docked into the COX active sites. The analysis includes use of the program GRID to detect isoenzyme differences near the active site region and is aimed at suggesting modifications of the basic benzophenone frame of the lead compound 2. The resulting series of compounds bearing this central framework is exemplified by the potent and selective COX-2 inhibitor 17 (LM-1669).

Analgesic, Antiinflammatory, and Antipyretic Effects of S(+)-Ketoprofen In Vivo.

Many studies indicate that the S-enantiomers of arylpropionic (APA) nonsteroidal antiinflammatory drugs (NSAIDs) are the pharmacologically active enantiomers. S(+)-ketoprofen (dexketoprofen) stereoselectively inhibits cyclooxygenase (COX) in vitro but very little is known about the differential activity of ketoprofen enantiomers in vivo. We examined the analgesic, antiinflammatory, and antipyretic activities of S(+)-ketoprofen in rats and mice. First, we measured the antinociceptive action of S(+)-ketoprofen in abdominal pain models. After intravenous administration, 0.5 mg/kg S(+)-ketoprofen inhibited 92.1 ± 2.2% of writhing in mice. Stereoselectivity in the activity was detected; intravenous administration of the R(-)-enantiomer resulted in no statistically significant activity in a dose range of 0.15-1 mg/kg. Similar results were obtained after oral administration in mice. In the rat, S(+)-ketoprofen was a more potent analgesic than diclofenac by both intravenous and oral administration. There was no significant difference between the analgesic effect of S(+)-ketoprofen treatment and the twofold dose of the racemic form in both the mouse and rat models. Second, we measured the antiinflammatory activity of S(+)-ketoprofen using a carrageenan-induced paw edema model in the rat. Intravenous administration of 5 mg/kg of S(+)-ketoprofen almost completely inhibited edema formation. After oral administration, S(+)-ketoprofen is both more potent and effective than diclofenac. Third, we measured antipyretic activity. S(+)-ketoprofen showed a marked antipyretic action (ED50 = 1.6 mg/kg) and was the most potent of the NSAIDs tested. S(+)-ketoprofen is a potent antiinflammatory, analgesic, and antipyretic agent in vivo, consistent with its potent anti-COX activity.

Intestinal Ulcerogenic Effect of S(+)-Ketoprofen in the Rat.

Nonsteroidal antiinflammatory drugs (NSAIDs) inhibit prostaglandin synthesis in the gastrointestinal mucosa, which can lead not only to stomach ulcers but also ulcers in the small and large intestines. Ulcers of the small intestine are less common than those of the stomach, but intestinal lesions are more life threatening. Although the R(-)-enantiomers of the arylpropionic acid (APA) class of NSAIDs are assumed to lack the toxic effects of cyclooxygenase inhibition, they may contribute to the ulcerogenicity of racemates. We have examined the intestinal ulcerogenic effects of single oral doses of S(+)-ketoprofen compared with racemic ketoprofen in the small intestine and cecum of rats. The toxicity in the small intestine was measured as the weight ratio between portions of intestine showing lesions and the total weight of the tissue. Toxicity in the cecum was evaluated by measuring the size of the ulcers. S(+)-ketoprofen had no significant ulcerogenic effect at 10 or 20 mg/kg. However, racemic ketoprofen was clearly ulcerogenic in the small intestine and cecum at the 40 mg dose. R(-)-ketoprofen at 20 mg/kg does not show any effect in the cecum and only limited ulcerogenesis in the small intestine: The latter effect may be the result of racemic inversion. Therefore, the ulcerogenic action of racemic ketoprofen can be interpreted as a synergism between S(+)- and R(-)-ketoprofen. The mechanism of this synergism is not well understood but may be a general feature of APA NSAIDs.

Bioavailability of S(+)-Ketoprofen After Oral Administration of Different Mixtures of Ketoprofen Enantiomers to Dogs.

Recent reports have disagreed on whether the bioavailability of S(+)-ketoprofen is affected by the presence of R(-)-ketoprofen. To examine this directly, we designed a randomized crossover study in beagle dogs. [14 C]- S(+)-ketoprofen trometamol and R(-)-ketoprofen trometamol were administered in the following percentage ratios: A, 99:1; B, 95:5; C, 90:10; D, 70:30; E, 50:50. Treatments were administered as a single oral dose of 1 mg/kg trometamol salt. Each of eight dogs received all five combinations in random order with a 1-week washout period between doses. Blood samples were taken before drug administration and at regular intervals for 240 min after dosing. A progressive increase in the plasma concentration of [14 C]-S(+)-ketoprofen was observed on going from treatment E (lowest dose of S-enantiomer) to treatments containing the highest doses of (14 C]-S(+)-ketoprofen. When the pharmacokinetic calculations were normalized to the dose of (14 C]-S(+)-ketoprofen, we found no statistically significant differences among the normalized AUC and Cmax values of the five treatments. Therefore, S(+)-ketoprofen absorption was linear and was not influenced by the presence of R(-)-ketoprofen. Furthermore, there were no significant differences in tmax values among treatments, indicating that the rate of S(+)-ketoprofen absorption was also unaffected by the presence of R(-)-ketoprofen.

Pharmacokinetics of Dexketoprofen Trometamol in Healthy Volunteers After Single and Repeated Oral Doses.

The pharmacokinetics of dexketoprofen trometamol were evaluated in two studies using healthy volunteers. In the first study, the relative bioavailability of a single oral capsule of dexketoprofen free acid 25 mg or dexketoprofen trometamol 25 mg (given as 37 mg of the trometamol salt) was compared to ketoprofen 50 mg in 18 healthy volunteers. In the second study, the pharmacokinetics and tolerability of oral dexketoprofen trometamol in tablet form were evaluated after either a single 25 mg dose (24 volunteers) or a repeated dose of 25 mg twice daily for 7 days (12 volunteers). The absorption of dexketoprofen from dexketoprofen trometamol capsules was bioequivalent to that of ketoprofen. On the other hand, the extent of absorption of dexketoprofen free acid was significantly lower than that for ketoprofen. Dexketoprofen trometamol showed the most rapid absorption rate, with highest Cmax and shortest tmax values, whereas dexketoprofen free acid had the slowest absorption rate, and ketoprofen had an intermediate absorption rate. After repeated-dose administration of dexketoprofen trometamol, the pharmacokinetic parameters were similar to those obtained after single doses, indicating that no drug accumulation occurred. Dexketoprofen trometamol was well tolerated, with no clinically relevant adverse events reported.