Pravastatin Transdermal Patches: Effect of The Formulation and Two Different Lengths of Microneedles on <i>In-vitro</i> Percutaneous Absorption Studies

Abstract

Transdermal patches loaded with pravastatin was previously characterized in another published study by Serrano-Castañeda et al; 2015. These transdermal patches (TP) were generated by the plate casting technique, the in-vitro percutaneous absorption studies of TP were evaluated for three different formulations with different quantities of Pluronic F-127 (PF-127): i) without PF-127 (TP W), ii) 1% of PF-127 (TP 1%), and iii) 3% of PF-127 (TP 3%) using solid microneedles as a penetration enhancer with two different lengths: i) 0.25 mm and ii) 2.25 mm and iii) in-vitro permeation studies by passive diffusion. The fluxes (F), time lag (tLag) and permeability constants (Kp) for each formulation were: TP W (F:38.5µg/cm2*h, tLag:18.97h and Kp:5.9x10-3 cm/h), TP W with microneedles of 0.25 mm (F:103.3 µg/cm2*h, tLag: 20.76 h and Kp: 0.0158 cm/h), TP W and microneedles of 2.25 mm (F:105.2µg/cm2*h, tLag: 21.16 h and Kp: 0.0159cm/h), TP 1% (F:90 µg/cm2*h, tLag: 19.48 h and Kp: 0.0137 cm/h), TP 1% with microneedles of 0.25 mm (F:111.4µg/cm2*h, tLag:19.11h and Kp:0.017cm/h), and TP 1% with microneedles of 2.25 mm (F:115.2µg/cm2*h, tLag:16.73h and Kp:0.017cm/h), TP 3% (F:40.9µg/cm2*h, tLag:20.45h and Kp:0.0062 cm/h), TP 3% with microneedles of 0.25 mm (F:67.1 µg/cm2*h, tLag: 21.79h and Kp:0.0102cm/h) and TP 3% with microneedles of 2.25 (F:70.5 µg/cm2*h, tLag:20.44h and Kp:0.0107cm/h). Results show that the formulation of TP affects the pravastatina flux and Kp parameters, however the length of microneedles only has important effect on tLag.