Abstract
The molecular and group surface area approach to solubility is shown to be applicable to mixed aqueous solvent systems. An equation is derived which is consistent with the exponential increase in the aqueous solubility of nonpolar drugs that frequently accompanies the addition of a cosolvent. This equation predicts that: (a) the ability of a drug to be solubilized by a cosolvent is proportional to its hydrophobic surface area per molecule, and (b) the ability of a cosolvent to solubilize any drug is inversely proportional to its interfacial tension against a reference liquid hydrocarbon. These predictions are experimentally verified with solubility studies of several alkyl p‐aminobenzoates in propylene glycol‐water mixtures and of hexyl p‐aminobenzoate in mixtures of water with ethanol, methanol, ethylene glycol, propylene glycol, glycerin, and formamide.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1488-1494 |
| Number of pages | 7 |
| Journal | Journal of pharmaceutical sciences |
| Volume | 65 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 1976 |
| Externally published | Yes |
Keywords
- Alkyl p‐aminobenzoates—solubility in propylene glycol‐water mixtures
- Cosolvent systems, polar—solubility of nonelectrolytes, molecular and group surface area approach
- Hexyl p‐aminobenzoate—solubility in mixed polar solvent systems
- Nonelectrolytes—solubility in mixed aqueous solvent systems
- Polar solvents, mixed—solubility of nonelectrolytes, molecular and group surface area approach
- Solubility—nonelectrolytes in mixed aqueous solvent systems, molecular and group surface area approach
ASJC Scopus subject areas
- Pharmaceutical Science