Chapter 8 Multiple Choice Questions

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. When considering partition and distribution coefficients which of the following statements is true?

A distribution coefficient considers the ratio of the concentration of a single definite form of a drug in one phase to that of the same form in the other phase correct incorrect

A partition coefficient considers the ratio of the total concentration of a drug in one phase to the total concentration in the other phase correct incorrect

A weakly basic drug would be expected to have a higher distribution coefficient from an acidic aqueous solution correct incorrect

A weakly acidic drug would be expected to have a higher distribution coefficient from an acidic aqueous solution correct incorrect

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. Which of the following solvents is the most suitable for determining partition coefficients which have relevance for drug transport across biological membranes

Liquid paraffin correct incorrect

Butanol correct incorrect

Heptane correct incorrect

Octanol correct incorrect

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. With regards to the measurement of partition coefficients, which of the following is true?

The shake flask method gives rapid results correct incorrect

Chromatographic methods are useful when log P values for several APIs are required correct incorrect

The shake flask method is useful for very hydrophilic and very hydrophobic compounds correct incorrect

Log P values obtained from computer programmes are preferable to those obtained from experimental measurements correct incorrect

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. When considering the selection of an organic solvent for log P measurement, which of the following is true?

A water miscible alcohol such as ethanol is suitable correct incorrect

Chloroform has the most supporting data for in vivo correlations correct incorrect

It has been suggested that consideration of partitioning in to more than one organic solvent would be useful when considering in vivo correlations correct incorrect

It is straightforward to calculate the log P of drugs into a variety of different solvents using a computer programme correct incorrect

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. When considering drug absorption across the gastrointestinal tract, partition coefficients are useful for

Indicating whether passive diffusion of a drug across a membrane is possible correct incorrect

Identifying whether the drug should be administered with or after food correct incorrect

Predicting whether active transport of the drug is likely to occur correct incorrect

Identifying whether the drug will degrade in the acidic conditions of the stomach correct incorrect

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. With regards to drug absorption across skin, which of the following is false?

The pH partition hypothesis can be applied to drug absorption across skin correct incorrect

A log P of 6 indicates that a drug will show good absorption across skin correct incorrect

A parabolic relationship exists between log P and skin permeability correct incorrect

The Potts and Guy equation is an example of a QSAR that uses log P to predict the skin permeability of a drug compound correct incorrect

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. When using log P when considering the preservation of emulsions, which of the following applies?

Temperature would not be expected to affect the concentration of a preservative in the two phases correct incorrect

It does not matter which organic phase is used to obtain the log P value correct incorrect

A higher preservative concentration is often required for arachis oil emulsions rather than liquid paraffin emulsions correct incorrect

The concentration of the preservative in the oil phase is what is important for preservation of the product correct incorrect

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. When considering the packaging of an IV infusion, which of the following is true?

Drug losses to packaging are always clinically insignificant correct incorrect

Drugs with narrow therapeutic windows are of the least concern when administering formulating an IV infusion correct incorrect

Glyceryl trinitrate is an example of a drug that has shown drug content losses to packaging correct incorrect

A greater proportion of warfarin is lost to packaging when the pH of the IV infusion fluid is 5.6 in comparison to 4.9 correct incorrect

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. When considering the distribution of drugs to human milk which of the following is true?

There is a considerable amount of clinical data concerning the distribution of drugs to the milk of breast feeding mothers correct incorrect

The log P of a drug can be used to estimate the exposure of a breastfeeding child to a drug administered to its mother correct incorrect

Citalopram and venlafaxine are two antidepressants the concentrations of which could not be predicted in breast milk correct incorrect

Understanding the distribution of drugs in breast milk is relatively simple and need only consider the partitioning of the drug from an aqueous phase to the fat droplets in the milk correct incorrect

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. When considering drug delivery to the brain which of the following is false?

The cells in the blood vessels that supply the brain are tightly connected which restricts drug absorption correct incorrect

Only relatively small lipophilic molecules readily, passively diffuse in to the brain correct incorrect

Drugs with a low log P value show improved passive diffusion into the brain correct incorrect

Polar molecules can be taken up into the brain through active transport correct incorrect