Molecular weight of drugs

The Molecular Weights of Drugs Delivered Transdermally, Either Commercially or Under Clinical Evaluation... 

Sakane, T., et al. 1995. Direct drug transport from the rat nasal cavity to the cerebrospinal-fluid. The relation to the molecular-weight of drugs. J Pharm Pharmacol 47 379. 

Fig.2. Correlation between dose of drug to be administered, amount of drug-complex to be tablet ed and molecular weight of drug BCD =1 1 complexes...

Typically, the administrated drug dose =5pg/g.tissue, molecular weight of drug=600 g/mole, tissue concentration of drug (D) =5x10 moles, liter the tissue den-... 

While there is a vast range of different drug structures, there are only a relatively small number of chemical reactions, some of which are shown below in Table 5.13 (p. 199), involved in the production of metabolites. Based on the structure of the drug, it is therefore possible to predict the most likely metabolites. Use may then be made of reconstructed ion chromatograms (RlCs) of mlz values corresponding to the predicted molecular weights of these metabolites to locate them within the LC-MS data obtained. 

The MS-MS spectrum of the (M + H)+ ion from the parent drug contains an ion at m/z 465, the structure of which is indicated in Figure 5.40. The mass spectrum of metabolite 1 indicates that it has a molecular weight of 482 Da, while the MS-MS spectrum from its MH+ ion contains both an ion at m/z 466 and aXm/z 364, also present in that from the MH+ of the parent drug. It is not unreasonable, although not necessarily always correct, to assume that the ion of... 

The electrospray mass spectrnm of metabolite 2 indicates it has a molecular weight of 522 Da, while the MS-MS spectrum of the (M + H)+ ion contains an intense ion at m/z 422, 1 Da greater than the base peak of the MS-MS spectrnm of the protonated molecnlar ion of the parent drug. If we assume a similar relationship between these ions as assnmed for m/z 465 and m/z 466 above, it is not nnreasonable to postnlate the strnctnre of metabolite 2 to be that shown in Fignre 5.44. 

One approach to drug metabolism studies is therefore to predict the molecular weights of possible metabolites of the drug under consideration, to use reconstructed ion chromatograms to locate any components that have the appropriate molecular weights and then use MS-MS to effect fragmentation of the (M - - H)+ ions from these metabolites, and then to finally link the m jz values of the ions observed with ions of known structure from the parent drug or from other metabolites whose structures have been elucidated. 

The rate of drug release was affected by the molecular weight of PLA used in the composite. 

In this case a different method was used 2 g polymer was dissolved in 10 ml of methylene chloride, drug was added, and the mixture was suspended in silicon oil containing Span 85 and a known amount of methylene chloride. The amount of methylene chloride depended on the type and molecular weight of the polymer used. For example. 

SI (le Systeme International d UniUs) units are used in many countries to express clinical laboratory and serum drug concentration data. Instead of employing units of mass (such as micrograms), the SI system uses moles (mol) to represent the amount of a substance. A molar solution contains 1 mol (the molecular weight of the substance in grams) of the solute in 1 L of solution. The following formula is used to convert units of mass to moles (mcg/mL to pmol/L or, by substitution of terms, mg/mL to mmol/L or ng/mL to nmol/L). 

Q = saturation solubility of drug (macroparticles) y = interfacial tension between drug particles and the solubilizing fluids M = Molecular weight of the drug r = radius of the microscopic drug particle R = ideal gas constant... 

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