Final answer:
The statement is true; topical ocular drugs require a balance between hydrophobic and hydrophilic properties to ensure both solubility and penetration through the lipid-rich ocular barriers.
Step-by-step explanation:
The statement that topical ocular drugs must be hydrophobic with some hydrophilic properties is true. The physicochemical properties of a drug determine its therapeutic efficacy and bioavailability. Topical ocular drugs must possess a certain degree of lipophilicity (hydrophobicity) to penetrate the lipid-rich ocular barriers such as the cornea. However, they must also have some hydrophilic properties to maintain solubility in the aqueous environment of the eye. It's a delicate balance: too hydrophobic, and the drug may not be soluble enough to be therapeutic; overly hydrophilic, and the drug may not pass through the lipid barriers effectively.
Compounds with hydrophobic properties, like small hydrophobic ligands that can diffuse through plasma membranes, interact with internal receptors. For example, steroid hormones, which are hydrophobic and lipid-soluble, can readily pass through cell membranes due to their structure and must bind to carrier proteins in the bloodstream to be soluble. Conversely, hydrophilic molecules struggle to pass through the hydrophobic interior of cellular membranes without assistance.
Therefore, developing topical ocular drugs requires careful consideration of their hydrophobic and hydrophillic properties to ensure they are effectively delivered, absorbed, and therapeutic. The balance between these characteristics is crucial for the drug's performance and patient safety.