Which of the following factors has maximum effect on filtration of a drug by the glomerulus ?: (A) Lipid solubility, (B) Plasma protein binding, (C) Degree of ionization, (D) Rate of tubular secretion
Answer is B. - Main Factors determining glomerular filtration

   Renal blood flow
   Plasma protein binding

- Lipid solubility does not affect glomerular filtration.
- Ionization determines tubular reabsorption. 
- Tubular secretion happens after glomerular filtration and so does not affect the process.