Drugs online research references
J Histochem Cytochem. 1996 May;44(5):531-5.
Electron microscopic demonstration of intracelluar promethazine accumulation sites by a precipitation technique: application to the cerebellar cortex of the mouse.
Muller T.
Institute for Anatomy, University of Mainz, Germany.
A method is described that allows electron microscopic identification of the phenothiazine neuroleptic promethazine after supravital intracardiac injection of high drug concentrations (greater than or equal to 3 %). The cerebellar cortex of the mouse was used for the investigation. This procedure is based on simultaneous fixation of drug and tissue by immersion in a paraformaldehyde-glutaraldehyde solution with the addition of phosphomolybdic acid. The electron microscopic investigation revealed that the drug could easily be identified as an electron-dense precipitate. Subpopulations of neurons exhibited a higher affinity for the drug than others, but no preference for any nerve cell type was detected. Closer study showed that promethazine accumulated primarily within the cytoplasm, where it was bound to the endoplasmic reticulum. Furthermore, promethazine storage was observed within mitochondria and vesicular structures. Drug binding was also seen in the regions of synapses but without any predilection for these structures. Because this precipitation technique also appears to be well-suited for the ultrastructural identification of other drugs, it offers multiple possibilities for application.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8627010&dopt=Abstract
J Pharm Biomed Anal. 1995 Oct;13(11):1321-9.
Analysis of pharmaceutical creams: a useful approach based on solid-phase extraction (SPE) and UV spectrophotometry.
Bonazzi D, Andrisano V, Gatti R, Cavrini V.
Dipartimento di Scienze Farmaceutiche, Universita di Bologna, Italy.
Solid-phase extraction (SPE) using C-18, diol and ion-exchange sorbents followed by UV spectrophotometric (conventional and derivative mode) assay was applied to the analysis of basic, acidic and neutral drugs commercially available in creams. A representative set of drugs (promethazine, chlorhexidine, benzydamine, ketoprofen, ibuprofen, fentiazac, piroxicam, fluorouracil, crotamiton and hydrocortisone acetate) was selected, and for each drug the appropriate SPE conditions (adsorption, washing and elution) were investigated to obtain a practical and reliable sample clean-up. It was shown that the developed SPE procedures were capable of removing interfering cream components (excipients including preservatives) allowing accurate spectrophotometric analyses to be performed. In some applications, derivative spectrophotometry was advantageous over the conventional absorption mode with respect to higher selectivity and versatility.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8634349&dopt=Abstract
Food Chem Toxicol. 1996 May;34(5):495-506.
Preclinical skin sensitization testing of antihistamines: guinea pig and local lymph node assay responses.
Robinson MK, Cruze CA.
Human Safety Department, Procter & Gamble Company and Procter & Gamble Pharmaceuticals, Miami Valley Laboratories, Cincinnati, OH 45253, USA.
Preclinical test methods for allergic contact sensitivity have been widely used for sensitization hazard identification and, with consideration of human exposure conditions, have also been valuable tools for sensitization risk assessment. For many years, the guinea pig has been the test species of choice with a variety of test methods developed to assess the sensitization response. More recently the local lymph node assay (LLNA) in mice has been developed to provide a more objective index of sensitization potential. The standardized methods have proven to be very well suited to most situations in which potential skin sensitization of a chemical needs to be assessed before human exposure. A potential difficulty with all these relatively limited exposure preclinical test methods, however, is in the ability to detect weak contact allergens that prove to be significant clinical allergens due to chronic topical exposure, exposure to compromised skin, and/or highly exaggerated exposure through transdermal delivery. This has been shown with the transdermal drug clonidine and might also be the case for topical antihistamines. The latter are considered significant clinical contact allergens, although predictive preclinical test data are minimal or lacking. A series of guinea pig (modified Buehler) tests with two common antihistamine compounds (triprolidine and diphenhydramine) and LLNA on these and two other compounds (chlorpheniramine and promethazine) was conducted. Positive Buehler test results required use of penetrating vehicle systems and a modified nine-induction patch regimen. Positive LLNA responses were obtained with all four materials (to varying degrees) only if the application site was pre-abraded or a penetrating vehicle (dimethylformamide) was used. These data support the notion that preclinical sensitization test methods can be modified to increase sensitivity. This may be critical for preclinical assessment of topical/transdermal drugs or other materials with chronic or high-concentration exposures in man.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8655100&dopt=Abstract
Herbs and Pharmaceuticals Online ||
Hair Million herbal formula for hair loss and hair growth ||
Wellstreet online pharmacy for click-order prescription medications ||
Altace Online Pharmacy ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Insurance plans and information ||
Insurance policies for all purposes ||
Antibiotics and prescription medications online literature ||