Camptothecin-Loaded Liposomes with α-Melanocyte-Stimulating Hormone Enhance Cytotoxicity Toward and Cellular Uptake by Melanomas: An Application of Nanomedicine on Natural Product

ABSTRACTIn this study, we attempted to develop functional liposomes loaded with camptothecin and attached to α-melanocyte-stimulating hormone (α-MSH) to target melanoma cells. The liposomes were mainly composed of phosphatidylcholine, cholesterol, and stearylamine, and were characterized by the vesicle size, zeta potential, camptothecin encapsulation efficiency, and release behavior. Results revealed that α-MSH liposomes possessed an average size of approximately 250nm with a surface charge of 60mV. Camptothecin was successfully entrapped by the targeted liposomes with an encapsulation percentage of nearly 95%. The liposomes provided sustained and controlled camptothecin release. Non-targeted liposomes with the drug exerted superior cytotoxicity against melanomas compared to the free control. Cell viability was reduced from 48% to 32% compared to conventional liposomes. Peptide ligand conjugation further promoted cytotoxicity to 18% viability, which was a 2.7-fold decrease versus the free control. According to the images of fluorescence microscopy, α-MSH liposomes exhibited greater cell endocytosis than did non-targeted liposomes and the free control. α-MSH liposomes were predominantly internalized in the cytoplasm. These findings demonstrate that α-MSH liposomes could enhance the anti-melanoma activity of camptothecin owing to their targeting ability and controlled drug delivery

Oil components modulate the skin delivery of 5-aminolevulinic acid and its ester prodrug from oil-in-water and water-in-oil nanoemulsions

The study evaluated the potential of nanoemulsions for the topical delivery of 5-aminolevulinic acid (ALA) and methyl ALA (mALA). The drugs were incorporated in oil-in-water (O/W) and water-in-oil (W/O) formulations obtained by using soybean oil or squalene as the oil phase. The droplet size, zeta potential, and environmental polarity of the nanocarriers were assessed as physicochemical properties. The O/W and W/O emulsions showed diameters of 216–256 and 18–125 nm, which, respectively, were within the range of submicron- and nano-sized dispersions. In vitro diffusion experiments using Franz-type cells and porcine skin were performed. Nude mice were used, and skin fluorescence derived from protoporphyrin IX was documented by confocal laser scanning microscopy (CLSM). The loading of ALA or mALA into the emulsions resulted in slower release across cellulose membranes. The release rate and skin flux of topical drug application were adjusted by changing the type of nanocarrier, the soybean oil O/W systems showing the highest skin permeation. This formulation increased ALA flux via porcine skin to 180 nmol/cm2/h, which was 2.6-fold that of the aqueous control. The CLSM results showed that soybean oil systems promoted mALA permeation to deeper layers of the skin from ∼100 μm to ∼140 μm, which would be beneficial for treating subepidermal and subcutaneous lesions. Drug permeation from W/O systems did not surpass that from the aqueous solution. An in vivo dermal irritation test indicated that the emulsions were safe for topical administration of ALA and mALA

Effect of Garden Cress Seeds Powder and Its Alcoholic Extract on the Metabolic Activity of CYP2D6 and CYP3A4

The powder and alcoholic extract of dried seeds of garden cress were investigated for their effect on metabolic activity of CYP2D6 and CYP3A4 enzymes. In vitro and clinical studies were conducted on human liver microsomes and healthy human subjects, respectively. Dextromethorphan was used as a common marker for measuring metabolic activity of CYP2D6 and CYP3A4 enzymes. In in vitro studies, microsomes were incubated with NADPH in presence and absence of different concentrations of seeds extract. Clinical investigations were performed in two phases. In phase I, six healthy female volunteers were administered a single dose of dextromethorphan and in phase II volunteers were treated with seeds powder for seven days and dextromethorphan was administered with last dose. The O-demethylated and N-demethylated metabolites of dextromethorphan were measured as dextrorphan (DOR) and 3-methoxymorphinan (3-MM), respectively. Observations suggested that garden cress inhibits the formation of DOR and 3-MM metabolites. This inhibition of metabolite level was attributed to the inhibition of CYP2D6 and CYP3A4 activity. Garden cress decreases the level of DOR and 3-MM in urine and significantly increases the urinary metabolic ratio of DEX/DOR and DEX/3-MM. The findings suggested that garden cress seeds powder and ethanolic extract have the potential to interact with CYP2D6 and CYP3A4 substrates

A comparison of skin delivery of ferulic acid and its derivatives: evaluation of their efficacy and safety.

Ferulic acid (FA) can be used as an antioxidant to prevent damage from ultraviolet (UV) radiation and skin carcinogenesis. To this end, the feasibility of the skin absorption of FA and its derivatives was evaluated in the present study. The percutaneous absorption of five compounds into/across porcine skin was measured and compared using Franz diffusion cells. The skin delivery from pH 6 and 9.9 buffers was the highest for ferulic acid ethyl ether (FAEE), followed by coniferyl aldehyde (CD), coniferyl alcohol (CA), FA, and 3-hydroxy-4-methoxycinnamic acid (HMA). The skin deposition and flux of FAEE with a pH 6 buffer were 136 nmol/g and 26 nmol/cm(2)/h, respectively. No significant difference in permeation profiles was observed between the two pH buffers. According to permeation via the skin with different treatments (delipidization, ethanol, and oleic acid treatments), it was determined that the lipid bilayers in the stratum corneum (SC) comprised the predominant barrier for FA permeation. On the other hand, FAEE could easily partition into and penetrate across the skin through intercellular pathways. Nude mouse was used as an in vivo animal model to examine the amount of permeants remaining in the skin. The in vivo skin deposition was generally correlated with the in vitro results. The in vivo skin deposition of FAEE (145 nmol/g) was comparable to that of CD (150 nmol/g). The safety study which examined transepidermal water loss (TEWL), erythema, and the skin pH value demonstrated that the topical application of FA and related compounds for up to 24h did not cause skin irritation. It can be concluded that topical delivery may serve as an efficient and safe route for FA and its derivatives against photodamage. Copyright © 2010. Published by Elsevier B.V. DOI: 10.1016/j.ijpharm.2010.07.05

Preparation, in vitro and in vivo evaluation of solid-state self-nanoemulsifying drug delivery system (SNEDDS) of vitamin A acetate

Vitamin A self-nanoemulsifying drug delivery system (SNEDDS), which comprises soybean oil, Cremophor EL, and Capmul MCM-C8, was prepared and mixed with different grades of Avicel to produce homogenized powders. The resultant powders were compressed into tablets. The prepared tablets were characterized for their thickness, hardness, friability, disintegration time, and dissolution rate. In addition, the relative bioavailability of the tablets in comparison to solid-state Vitamin A oily solution (SSVAOS) tablets was investigated in rats. Vitamin A dissolution rate was markedly different from one formulation to another. From the bioavailability data, it was observed that Vitamin A SNEDD tablets have higher bioavailability (relative bioavailability 143.68%) compared with SSVAOS tablets. The AUC and Cmax of Vitamin A SNEDD tablets were found to be significantly different from that of SSVAOS tablets. DOI: 10.1080/1061186090300276

Formation of Leukotrienes From Calcium Ionophore-A23187 Stimulated Rabbit, Rat and Mice White Blood Cells

Leukotrienes (LTs) producing capacity was investigated in calcium ionophore A23 187- stimulated rabbit. rat and mice peripheral white blood cells suspension. A reverse phase high performance liquid chromatography technique and computerized UV spectroscopy were employed to isolate and quantitate the released LTs namely. LTC4 and LTB4. Preincubation of rabbit white blood cells at 37°C for 5 min followed by calcium ionophore-A23 187 (1 pM) stimulation for another 5 min produced an equal amounts of LTC4 as compared to LTC4 produced by human white blood cells (105±11 versus 95±9.5 pmol/107 cells respectively; mean ±SEM). In contrast rabbit white blood cells synthesized significantly lower LTB4 in comparison with LTB4 produced by peripheral white blood cells from healthy control (168±18 versus 228±19 pmol/107 cells respectively: mean ±SEM). When rat and mice white blood cells suspension were stimulated with calcium ionophore A23187 (1 µM) after preincubation at 37°C for 5 min, equivalent amounts of LTC4 and LTB4 were observed. However, LTB4 and LTC4 produced by rat and mice white blood cells were significantly lower in comparison with LTB4 and LTCj produced by human white blood cells stimulated with calcium ionophore-A23 187. These results demonstrate that rabbit. rat and mice white blood cells suspension possess the capacity to produce LTC4 and LTB4 from endogenous substrate after calcium ionophore-A23 187 stimulation

Evaluation of skin permeation and analgesic activity eff ects of carbopol lornoxicam topical gels containing penetration enhancer, Sci

The current study was designed to develop a topical gel formulation for improved skin penetration of lornoxicam (LOR) for enhancement of its analgesic activity. Moreover, the effect of different penetration enhancers on LOR was studied. The LOR gel formulations were prepared by using hydroxylpropyl methylcellulose (HPMC) and carbopol. The carbopol gels in presence of propylene glycol (PG) and ethanol were developed. The formulated gels were characterized for pH, viscosity, and LOR release using Franz diffusion cells. Also, in vitro skin permeation of LOR was conducted. The effect of hydroxypropyl -cyclodextrin (HP -CD), beta-cyclodextrin ( -CD), Tween 80, and oleic acid on LOR permeation was evaluated. The optimized LOR gel formulation (LORF8) showed the highest flux (14.31 g/cm 2 /h) with ER of 18.34 when compared to LORF3. Incorporation of PG and HP -CD in gel formulation (LORF8) enhanced the permeation of LOR significantly. It was observed that LORF3 and LORF8 show similar analgesic activity compared to marketed LOR injection (Xefo). This work shows that LOR can be formulated into carbopol gel in presence of PG and HP -CD and may be promising in enhancing permeation

Evaluation of Skin Permeation and Analgesic Activity Effects of Carbopol Lornoxicam Topical Gels Containing Penetration Enhancer

The current study was designed to develop a topical gel formulation for improved skin penetration of lornoxicam (LOR) for enhancement of its analgesic activity. Moreover, the effect of different penetration enhancers on LOR was studied. The LOR gel formulations were prepared by using hydroxylpropyl methylcellulose (HPMC) and carbopol. The carbopol gels in presence of propylene glycol (PG) and ethanol were developed. The formulated gels were characterized for pH, viscosity, and LOR release using Franz diffusion cells. Also, in vitro skin permeation of LOR was conducted. The effect of hydroxypropyl β-cyclodextrin (HP β-CD), beta-cyclodextrin (β-CD), Tween 80, and oleic acid on LOR permeation was evaluated. The optimized LOR gel formulation (LORF8) showed the highest flux (14.31 μg/cm2/h) with ER of 18.34 when compared to LORF3. Incorporation of PG and HP β-CD in gel formulation (LORF8) enhanced the permeation of LOR significantly. It was observed that LORF3 and LORF8 show similar analgesic activity compared to marketed LOR injection (Xefo). This work shows that LOR can be formulated into carbopol gel in presence of PG and HP β-CD and may be promising in enhancing permeation