ISSN:
1573-904X
Keywords:
Melanotan-I
;
poly (D,L-Lactide-co-glycolide)
;
pharmacologic response
;
controlled-release
;
melanogenesis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Purpose. The objective of this study was to evaluate in vitro and invivo the melanogenic activity of one-month duration Melanotan-I(MT-I) implants prepared using poly (D,L lactide-co-glycolide) polymer. Methods. The biological activity of the samples of MT-I released invitro from the non-irradiated or gamma irradiated implants wasmeasured using a frog skin bioassay. The effect of MT-I on skinpigmentation was measured using a Chroma meter (reflectometer) aftersubcutaneous administration of implants containing 4 mg MT-I toguinea pigs. Eumelanin, the black/brown melanin pigment, wasquantified in skin biopsies as pyrrole-2, 3, 5-tricarboxylic acid using HPLC. Results. The MT-I released in vitro from implants after 24 hoursexhibited 100% melanotropic activity in frog skins compared to an identicalconcentration of a freshly prepared MT-I standard. The reflectancereadings demonstrated a prolonged skin darkening for up to threemonths as evidenced by the decrease in the luminance values from 0to −4.82. A 2.5-fold increase in eumelanin levels was observed afterone month and the increased pigmentation lasted for 3 months. Conclusions. The melanogenic response to MT-I implants persisted forthree months and the increase in pigmentation, especially the increasedeumelanin levels, could provide protection from ultraviolet radiation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007525117894
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