In Vitro and In Vivo Skin Distribution of 5α-Reductase Inhibitors Loaded Into Liquid Crystalline Nanoparticles.

In this study, we developed positively charged liquid crystalline nanoparticles (LCN) coated with chitosan (CHI) to enhance the skin permeation and distribution of 5α-reductase inhibitors for the treatment of androgenetic alopecia. LCN and surface-modified LCN (CHI-LCN) were prepared by ultrasonication method, and their physicochemical properties were characterized. In vitro and in vivo skin permeation and retention were studied using porcine abdominal skin and mice skin using the Franz diffusion cell. Skin distribution and cellular uptake of LCN and CHI-LCN were also investigated. The particle size and surface charge were 244.9 ± 2.1 nm and -19.2 ± 1.1 mV, respectively, for LCNs and 300.0 ± 7.6 nm and 24.7 ± 2.4 mV, respectively, for CHI-LCN. The permeation of 5α-reductase inhibitors was significantly greater with CHI-LCN compared with LCN, whereas there was no significant difference observed in the skin distribution. In fluorescence studies, fluorescence intensity was higher for CHI-LCNs throughout the skin, whereas more intense fluorescence was seen only in the epidermis layer for LCN. CHI-LCN showed greater cellular uptake than LCN, resulting in internalization of 98.5 ± 1.9% of nanoparticles into human keratinocyte cells. In conclusion, surface modification of LCN with CHI is a promising strategy for increasing skin permeation of 5α-reductase inhibitors for topical delivery.

Synthesis of decapeptide of L-aspartic acid and benzyl-L-aspartic acid by solid phase peptide synthesis.

Polyene macrolide amphotericin B (AmB) is the drug of choice for the treatment of disseminated fungal infections. However, because of its pronounced side effects, the drug has limited applicability. There are few interesting reports, which state that co-administration of the drug with homo-peptide of polyaspartic acid reduces the side effects of the drug. In our present study, an approach has been made to systematically synthesize low molecular weight heteropeptides consisting of L-aspartic acid and its derivative. It was hypothesized that such heteropeptides will reduce the toxic side effects of the drug by facile hydrophobic binding between the polymer and the drug. We have employed the strategy of solid phase peptide synthesis (SPPS) to synthesize low molecular weight hetero-peptides by using L-aspartic acid and benzyl-L-aspartic acid to induce the hydrophobic binding between the peptide and the drug. In future, the proposed methodology can be employed to tailor other polypeptides substituted with benzyl groups to reduce the nephrotoxicity of AmB.

Gemifloxacin: a new fluoroquinolone approved for treatment of respiratory infections.

OBJECTIVE: To evaluate the microbiology, pharmacokinetic parameters, drug interactions, and results of the available clinical trials of gemifloxacin for the treatment of community-acquired pneumonia (CAP) and acute exacerbation of chronic bronchitis (AECB). DATA SOURCES: MEDLINE (1966-September 2003) was searched for primary and review articles. Data from the manufacturer were also included. Key words included adverse effects, clinical trials, drug interactions, gemifloxacin, and pharmacokinetic parameters. STUDY SELECTION AND DATA EXTRACTION: All articles and product labeling concerning gemifloxacin, a fluoroquinolone antibiotic recently approved by the Food and Drug Administration for treatment of CAP and AECB, were included for review. DATA SYNTHESIS: Compared with currently available fluoroquinolones, gemifloxacin demonstrated improved in vitro activity against Streptococcus pneumoniae (minimum inhibitory concentration for 90% eradication 0.03 microg/mL) and similar activity against gram-negative respiratory pathogens (Haemophilus influenzae, Moraxella catarrhalis) and atypical pathogens such as Chlamydia pneumoniae, Legionella pneumophila, and Mycoplasma pneumoniae. Gemifloxacin, consistent with other available fluoroquinolones, has insufficient activity against methicillin-resistant Staphylococcus aureus to allow clinical use for such infections. Gemifloxacin has adequate bioavailability and a favorable drug interaction profile. Gemifloxacin was comparable to commonly employed nonfluoroquinolone regimens for treatment of CAP and AECB, although the studies were designed to demonstrate equivalence. Gemifloxacin once daily for 5-7 days was well tolerated in controlled and uncontrolled clinical studies. Available clinical data, however, are insufficient to draw clinical or toxicologic distinctions between gemifloxacin and other fluoroquinolones. CONCLUSIONS: Gemifloxacin may be a suitable choice for empiric treatment of CAP or AECB. However, due to the significant history of fluoroquinolone-induced hepatic failure and dermatologic complications, the use of this drug should be closely monitored.