Bioavailability of progesterone enhanced by intranasal spraying

Area of Science:

• Pharmacokinetics
• Neuroendocrinology
• Drug Delivery Systems

Background:

• Progesterone (P) is a crucial hormone with therapeutic potential.
• Efficient delivery of progesterone to systemic circulation and the central nervous system is challenging.
• Understanding bioavailability across different administration routes is vital for effective treatment.

Purpose of the Study:

• To compare the bioavailability of progesterone administered via nasal spray, intravenous (IV), intramuscular (IM) injections, nasal drops, and eye drops.
• To assess progesterone levels in serum and cerebrospinal fluid (CSF).
• To determine the optimal route for enhanced progesterone delivery.

Main Methods:

• Adult ovariectomized rhesus monkeys were used as the study model.
• Progesterone was administered through various routes: nasal spray, IV injection, IM injection, nasal drops, and eye drops.
• Serum and cerebrospinal fluid concentrations of progesterone were measured over time.
• Area under the time-concentration curve (AUC) and maximal concentration (Cmax) were calculated to assess bioavailability.

Main Results:

• Intranasal progesterone spray demonstrated significantly higher bioavailability in both serum and cerebrospinal fluid compared to other tested methods.
• AUC and Cmax values were considerably elevated with the nasal spray formulation.
• Other routes, including IV and IM injections, showed lower systemic and CNS bioavailability.

Conclusions:

• Nasal spray administration is a superior method for achieving high progesterone bioavailability in both systemic and central nervous system compartments.
• This finding suggests intranasal progesterone spray as a promising delivery system for therapeutic applications requiring efficient progesterone distribution.
• Further research may explore clinical applications of intranasal progesterone delivery.