In vitro dissolution rates of six 8-methoxypsoralen formulations.

Area of Science:

• Pharmacology
• Drug Delivery
• Dermatology

Background:

• Psoralen-UVA (PUVA) therapy requires effective skin drug concentrations during irradiation.
• Oral 8-methoxypsoralen (8-MOP) is a key component in PUVA therapy.
• Assessing dissolution rates is crucial for ensuring therapeutic efficacy.

Purpose of the Study:

• To determine and compare dissolution rates of oral 8-methoxypsoralen formulations using two distinct methods.
• To propose a dissolution rate requirement for 8-MOP formulations to ensure adequate tissue concentrations for PUVA therapy.
• To identify formulations with satisfactory dissolution profiles.

Main Methods:

• Dissolution rates of six oral 8-methoxypsoralen formulations were evaluated using the rotating basket method.
• A column-type flow-through dissolution method was also employed for comparison.
• Formulations were assessed against a proposed dissolution requirement of at least 80% within 25 minutes.

Main Results:

• Both the rotating basket and flow-through methods yielded comparable and reproducible dissolution rate results.
• None of the three 8-MOP preparations registered in The Netherlands met the proposed dissolution requirement.
• Two imported 8-MOP preparations and a newly formulated capsule with 8-MOP in polyethylene glycol 6000 demonstrated satisfactory dissolution profiles.

Conclusions:

• The rotating basket and flow-through methods are suitable for assessing 8-MOP dissolution rates.
• Current registered 8-MOP formulations in The Netherlands may not provide optimal drug delivery for PUVA therapy.
• Improved 8-MOP formulations, particularly those utilizing enhanced dispersion techniques, show potential for effective PUVA treatment.