[Improving bioavailability of naftopidil by using bioadhesion in dogs]

Area of Science:

• Pharmacology
• Drug Delivery Systems
• Bioavailability Studies

Background:

• Naftopidil is a medication requiring optimized delivery for improved therapeutic outcomes.
• Sustained-release formulations aim to enhance drug efficacy and patient compliance.
• Bioadhesive properties can prolong drug residence time at absorption sites.

Purpose of the Study:

• To formulate and characterize naftopidil bioadhesive sustained-release capsules.
• To evaluate the pharmacokinetics and relative bioavailability of these novel capsules in dogs.
• To compare the performance of bioadhesive formulations against conventional naftopidil capsules.

Main Methods:

• Preparation of naftopidil bioadhesive sustained-release capsules using hydroxypropyl methylcellulose (HPMC) and Carbopol 934 (CP 934).
• A crossover study in five healthy male dogs administering naftopidil capsules and two bioadhesive formulations.
• Plasma naftopidil concentrations analyzed using a validated High-Performance Liquid Chromatography (HPLC) method.

Main Results:

• Bioadhesive sustained-release capsules showed significantly higher C0-->infinity, Cmax, and Tmax compared to conventional capsules.
• Relative bioavailability of the bioadhesive formulations was approximately 150-154% higher than the non-bioadhesive capsule.
• Pharmacokinetic parameters indicated a substantial improvement in drug absorption with bioadhesive formulations.

Conclusions:

• Bioadhesion significantly enhances the bioavailability of naftopidil.
• Naftopidil bioadhesive sustained-release capsules offer a promising approach for improved drug delivery.
• The developed formulations demonstrate superior pharmacokinetic performance over conventional naftopidil capsules.