Drugs online research references








J Pharm Pharmacol. 1999 May;51(5):565-76.
Characterization and in-vivo ocular absorption of liposome-encapsulated acyclovir.

Fresta M, Panico AM, Bucolo C, Giannavola C, Puglisi G.

Department of Pharmaceutical Sciences, University of Catania, Italy.

The potential of liposomes as an in-vivo ophthalmic drug delivery system for acyclovir was investigated. The drug-membrane interaction was evaluated by means of differential scanning calorimetry analysis. These experiments showed that acyclovir is able to interact with both positively and negatively charged membranes via electrostatic or hydrogen bonds. No interaction was observed with neutral membranes made up of dipalmitoylphosphatidylcholine. Different liposome preparation procedures were carried out to encapsulate acyclovir. The drug encapsulation mainly depends on the amount of water which the liposome system is able to entrap. In the case of multilamellar vesicles, charged systems showed the highest encapsulation efficiency. No particular difference in the encapsulation efficiency was observed for oligolamellar vesicles prepared with the reverse-phase evaporation technique. Oligolamellar liposomes showed the highest acyclovir encapsulation parameters and had release profiles similar to those of multilamellar liposomes. In-vivo experiments using male New Zealand albino rabbits were carried out to evaluate the aqueous humour concentration of acyclovir bioavailability. The most suitable ophthalmic drug delivery system was oligolamellar systems made up of dipalmitoylphosphatidylcholine-cholesterol-dimethyldioctadecyl glycerole bromide (7:4:1 molar ratio), which presented the highest encapsulation capacity and were able to deliver greater amounts of the drug into the aqueous humour than a saline acyclovir solution or a physical liposome/drug blend.

online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10411216&dopt=Abstract




Int J Pept Protein Res. 1994 Jun;43(6):573-82.
Activity of two synthetic amphiphilic peptides and magainin-2 against herpes simplex virus types 1 and 2.

Aboudy Y, Mendelson E, Shalit I, Bessalle R, Fridkin M.

Central Virology Laboratory, Chaim Sheba Medical Center, Tel Hashomer, Israel.

The in vitro antiviral activity of two amphiphilic synthetic peptides, modelin-1 (mod-1) and modelin-5 (mod-5), and of the natural antibacterial peptide magainin-2 (mag-2) against herpes simplex viruses type 1 (HSV-1) and 2 (HSV-2) were evaluated. The peptides were incubated with the virus, i.e. direct inactivation, and their effects examined by means of plaque reduction assay and/or reduction in virus yield. Only mod-1 displayed a strong antiviral effect against HSV-1 and HSV-2, with 50% effective dose (ED50) values of 4.6 and 4.1 micrograms/mL, respectively. Mag-2, mod-5 and a mixture of both had no significant inhibitory effect. Addition of mod-1 up to a concentration of 100 micrograms/mL to the culture medium had no significant cytotoxic effect on host vero cells, as measured by the trypan blue-exclusion method. It showed, however, considerable hemolytic activity against human red blood cells. Experiments including acyclovir (ACV) as a reference viral inhibitor indicated that the mode of action of mod-1 is different from that of ACV. In contrast to ACV, the peptide inactivates the virus following a very short incubation before vero cell infection, suggesting some kind of direct interaction of the peptide with the viral envelope, rather than inhibition of viral DNA replication or gene expression. Our results suggest that mod-1 may be an effective topical antiviral agent against herpes viruses.

online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7928088&dopt=Abstract

mdanderson.org

OBJECTIVE: To evaluate the physical compatibility of gemcitabine hydrochloride (Gemzar-Eli Lilly and Company) with 107 selected drugs. DESIGN: Controlled experimental trial. SETTING: Laboratory. INTERVENTIONS: Samples of 5 mL gemcitabine (as the hydrochloride salt) 10 mg/mL in 0.9% sodium chloride injection were mixed with 5 mL samples of the selected drugs diluted in 0.9% sodium chloride injection or, if necessary to avoid incompatibilities with the diluent, 5% dextrose injection. MAIN OUTCOME MEASURES: Visual examinations of the samples were performed in normal fluorescent light with the unaided eye and using a Tyndall beam (high-intensity monodirectional light) to enhance visualization of small particles and low-level haze. The turbidity of each sample was measured as well. In selected samples, electronic particle content assessment was performed. All of the samples were assessed initially and at 1 and 4 hours. RESULTS: Most of the drugs were physically compatible with gemcitabine hydrochloride during the 4-hour observation period. However, 15 drug combinations had incompatibilities that included color change, increase in haze or turbidity, particulate formation, and gross precipitation: acyclovir sodium, amphotericin B, cefoperazone sodium, cefotaxime sodium, furosemide, ganciclovir sodium, imipenem-cilastatin sodium, irinotecan, methotrexate sodium, methylprednisolone sodium succinate, mezlocillin disodium, mitomycin, piperacillin sodium, piperacillin sodium/tazobactam sodium, and prochlorperazine edisylate. CONCLUSION: Gemcitabine hydrochloride 10 mg/mL admixed in a compatible infusion solution is physically compatible for 4 hours at room temperature with 92 of 107 tested drugs. Simultaneous Y-site administration of gemcitabine hydrochloride with the 15 drugs resulting in incompatibilities should be avoided.

online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10467816&dopt=Abstract












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