The objective of the present study was to investigate the influence of the encapsulation\nefficiency and size of liposome on the oral bioavailability of griseofulvin-loaded liposomes.\nGriseofulvin-loaded liposomes with desired characteristics were prepared from pro-liposome\nusing various techniques. To study the effect of encapsulation efficiency, three preparations of\ngriseofulvin, namely, griseofulvin aqueous suspension and two griseofulvin-loaded liposomes with\ndifferent amounts of griseofulvin encapsulated [i.e., F1 (32%) and F2(98%)], were administered to\nrats. On the other hand, to study the effect of liposome size, the rats were given three different\ngriseofulvin-loaded liposomes of various sizes, generated via different mechanical dispersion\ntechniques [i.e., FTS (142 nm), MS (357 nm) and NS (813 nm)], but with essentially similar\nencapsulation efficiencies (about 93%). Results indicated that the extent of bioavailability of\ngriseofulvin was improved 1.7ââ?¬â??2.0 times when given in the form of liposomes (F1) compared to\ngriseofulvin suspension. Besides that, there was an approximately two-fold enhancement of the\nextent of bioavailability following administration of griseofulvin-loaded liposomes with higher\nencapsulation efficiency (F2), compared to those of F1. Also, the results showed that the extent of\nbioavailability of liposomal formulations with smaller sizes were higher by approximately three\ntimes compared to liposomal formulation of a larger size. Nevertheless, a further size reduction of\ngriseofulvin-loaded liposome (ââ?°Â¤400 nm) did not promote the uptake or bioavailability of griseofulvin.\nIn conclusion, high drug encapsulation efficiency and small liposome size could enhance the oral\nbioavailability of griseofulvin-loaded liposomes and therefore these two parameters deserve careful\nconsideration during formulation.
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