A stability-indicating micellar electrokinetic chromatography (MEKC) method was developed and validated for simultaneous analysis of delapril (DEL) and manidipine (MAN) using salicylic acid as an internal standard. The MEKC method was performed using a fused-silica capillary (effective length of 72 cm) with 50 mM of borate buffer and 5 mM of anionic surfactant sodium dodecylsulfate at pH 9.0 as the background electrolyte. The separation was achieved at 25 kV applied voltage and 35 degrees C. The injection was performed at 50 mbar for 5 s, with detection at 208 nm. The method was linear in the range of 15-150 microg/mL (r2 = 0.9966) for DEL and 5-50 microg/mL (r2 = 0.9985) for MAN with adequate results for the precision (< or = 1.87%) and accuracy (98.94% for DEL and 100.65% for MAN). The specificity of the method and its stability-indicating capability was demonstrated through forced degradation studies, which showed that there was no interference from the excipients. The Plackett-Burman experimental design was used for robustness evaluation, giving results within the acceptable range. The method was successfully applied for analysis of the drugs, and the results were compared to an LC method, resulting in nonsignificant differences (P = 0.78 and 0.84 for DEL and MAN, respectively).
A successful formulation (penciclovir hydrogel nanoemulsion - HN) to be used in transdermal drug delivery route to treat herpes simplex virus was developed and an analytical method to quantify penciclovir (PCV) in porcine ear skin was stablished and validated. PCV nanoemulsions were prepared by high pressure homogenization and presented spherical mean droplet size 180 nm. The association efficiency and zeta potential were 87% and– 27 mV, respectively. The bioanalytical method developed showed specificity for the interferences from the skin matrixes (epidermis and dermis) and the linearity was in the range 0.1 – 25 μg/mL of drug, The mean recovery data for the three levels tested were 95.2% for the epidermis and 97.3% for the dermis and adequate results were obtained for repeatability and inter-day precision. In vitro percutaneous absorption studies with the PCV nanoemulsion and a market cream were conducted employing the porcine skin.The cumulative amounts of PCV permeated from cream and HN, 8 h after dosing, were 2.60 and 4.15 μg/cm², respectively, representing a quite higher flux and a much higher permeability coefficient for the developed formulation. It can be concluded that HN provide a good skin targeting effect and may be a promising carrier for topical delivery of penciclovir.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.