Kinetic assessment on in vitro release studies of TDF-LM-EFZ loaded SLN by simultaneous equation method

Abstract

Introduction: The union of Tenofovir disoproxil fumarate (TDF), efavirenz (EFZ), lamivudine (LM), in any regimen is widely accepted as HAART therapy to diminish the progress of related opportunistic infection, reduced resistance to drug on prolonged therapy, and adoption of the simultaneous spectroscopic estimation of concentration of pharmaceuticals in dosage regimen make a time saving approach. Materials and method: TDF-EFZ-LM loaded compritol solid nanoparticles with lipid developed by double emulsification solvent vaporization technique. The λmax of TDF, EFZ and LM 259nm, 247nm and 272nm were resolved spectrophotometrically and combined spectra were plotted. Surface morphological studies showed discrete, spherical particles. The SLN-encapsulated capsules' release of drugs in vitro tests was carried out within 0.1 N hydrochloric acid and with phosphate buffer, pH 6.8 (PB).  Only 8%, 10% and 11% EFZ, TDF and LM were released in early 2 hours in acidic 0.1N hydrochloric acid whereas 73%, 83% and 86% EFZ, TDF and LM release was observed for the PH 6.8 buffer in the upcoming12 hours. By fitting the pharmaceutical discharge data of the optimized composition in zero, first order, Higuchi, Korsmeyer peppas kinetic equations, the drug dissolution pattern of the composition was identified. Conclusion: The higher R2 scores in Higuchi and zero-order concept indicated a diffusion regulated, concentration independent release kinetics. The diffusion coefficient determination in Koresmeyer- Peppas hypothesis for TDF, LM, EFZ 0.8474, 0.8477, 0.8325 signifies that release process is anomalous (combination of diffusion and erosion) and accompanies non- fickian diffusion.