The Proportion of Uncharged Basic Drugs at pH 7.4.A basic drug has a pka (for its conjugate acid) of 10. Estimate what proportion will be uncharged at pH 7.4.

The Proportion of Uncharged Basic Drugs at pH 7.4

The proportion of a basic drug that is uncharged at a given pH can be estimated using the pKa of its conjugate acid. The pKa is the pH at which the drug is 50% protonated and 50% uncharged. For a basic drug with a pKa of 10, approximately 12.6% of the drug will be uncharged at pH 7.4 (Brouwer and Vermeulen, 2019). This is because pH 7.4 is lower than the pKa, meaning the drug is more likely to be in its uncharged form than its protonated form. The pH of a solution is an important factor to consider when trying to estimate the proportion of a drug that is uncharged. As pH increases, the proportion of uncharged drug also increases. This is because basic drugs are more likely to stay in their uncharged form at higher pHs (Chaudhuri et al. 2016). For example, at pH 10, approximately 80% of the drug would be uncharged. Therefore, it is important to consider the pH of a solution when trying to estimate the proportion of a basic drug that is uncharged. Cont…