Fig 1.

Nanoencapsulation of the hydrophilic antimycobacterial drug isoniazid. Nanoparticles containing INH were prepared as described in Materials and Methods, and drug content (μg ml⁻¹) (A, D, and G), entrapment efficiency (%) (B, E, and H), and drug recovery (%) (C, F, and I) were determined by RP-HPLC following several technical procedures and external-phase pH variation. (A to C) Double emulsion technique; (D to F) nanoprecipitation; (G to I) nanoprecipitation salting-out procedure using NaCl. Results are means ± standard errors of the means (SEM) of measurements from triplicates. The results shown are representative of at least three independent experiments performed. An asterisk indicates statistically significant difference (P < 0.05 by Student's t test) in measurements between pH 5.0 and 7.0.