Increased partitioning of pilocarpine to the oily phase of submicron emulsion does not result in improved ocular bioavailability.
Submicron emulsions containing pilocarpine as ion-pair with mono-dodecylphosphoric acid were prepared. Physical stability of these preparations was confirmed during 4 months of storage at 4 degrees C. Approximately 50% of the drug was found in the aqueous phase of emulsion separated using an ultrafiltration technique, while the rest was present in the oily phase and interphase. The miotic effect observed in rabbits after application of the ion-pair in aqueous solution or in submicron emulsion was the same; indicating that the drug distribution into the oily phase of the colloidal vehicle does not improve ocular bioavailability.
Department of Pharmaceutical Technology, Medical University of Gdansk, ul. Hallera 107, 80-416, Gdansk, Poland. msznito@farmacja.amg.gda.pl
M
M
Sznitowska
K
K
Zurowska-Pryczkowska
E
E
Dabrowska
S
S
Janicki
D000818:Animals; D004337:Drug Carriers; D004655:Emulsions / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D007498:Iris / Q000378:metabolism*; D008081:Liposomes; D008916:Miotics / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D010862:Pilocarpine / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D011680:Pupil / Q000187:drug effects*; D011817:Rabbits; D013024:Soybean Oil / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics
D004337:Drug Carriers; D004655:Emulsions; D008081:Liposomes; D008916:Miotics; D010862:Pilocarpine; D013024:Soybean Oil