The multiple dose pharmacokinetics of isotretinoin and its major blood metabolite, 4-oxo-isotretinoin, were studied in 10 patients with cystic acne and 11 patients with various keratinization disorders. Blood samples were obtained at predetermined times following the first dose, interim doses and the final dose. Blood concentrations of isotretinoin and 4-oxo-isotretinoin were measured by a specific and sensitive HPLC method. A lag time was usually observed prior to the onset of absorption following oral administration of the drug in a soft elastic gelatin capsule. Absorption then proceeded rapidly and maximum blood concentrations usually occurred within 4 h of drug administration. The harmonic mean half-life for the elimination of isotretinoin by the cystic acne patients was approximately 10 h after the initial dose and did not change significantly following 25 days of 40 mg b.i.d. dosing. Steady-state blood concentrations remained relatively constant after the fifth day of dosing. The harmonic mean elimination half-life in the patients with various disorders of keratinization was about 16 h. The results of the 2 studies suggest that no significant changes in the pharmacokinetics of isotretinoin occur during multiple dosing and that the multiple dose pharmacokinetic profile is predictable and can be described using a linear pharmacokinetic model. This suggests that the steady-state concentrations of isotretinoin can be predicted from single dose data.
Methods: In this Phase I, multicenter, double-masked, randomized, placebocontrolled, ascending-dose study, subjects with bilateral OHT or early POAG (.22 mm Hg) received one of four concentrations of INS115644 (Lat-B ophthalmic solutions, 0.005%, 0.01%, 0.02%, or 0.05%) in one eye over 3 days (5 single-dose instillations, separated by 12 hours). One eye was randomly assigned to active drug, the other to placebo. IOP was measured prior to treatment initiation (day 0) and on days 1 and 3.Results: Baseline IOPs were 22.9 6 2.4 mm Hg and 23.5 þ 3.1 mm Hg in the 0.02% and 0.05% dose groups, respectively. At 4 hours post instillation of the first dose, 0.02% INS115644 reduced IOP from baseline (mean 6 SE) by 3.8 6 0.7 mm Hg (P ¼ 0.002) and 0.05% by 3.9 6 1.0 mm Hg (P ¼ 0.004). A maximum IOP decrease of 24% was noted at 4 hours after the fifth instillation of 0.02%. Adjusting for diurnal baseline and IOP in the contralateral, placebo-treated eye, the maximal 12-hour hypotensive effect was 4.0 6 0.5 mm Hg (adjusted mean 6 SE), a 17% decrease, following the fifth instillation of 0.02% (day 3). Adverse events were few and consisted mainly of mild redness, irritation, and a transient, clinically insignificant increase ( 2.5%) in central corneal thickness.
Conclusions:In OHT or POAG patients, twice daily Lat-B significantly lowered IOP compared with contralateral, placebo-treated eyes, with few and mild ocular adverse events.Translational Relevance: Lat-B may be a potential therapeutic agent for glaucoma.
PurposeKPI-121 is a nanoparticle suspension of loteprednol etabonate with improved ocular pharmacokinetics compared with marketed formulations. The efficacy and safety of KPI-121 1% ophthalmic suspension (INVELTYS™) dosed twice daily (BID) were evaluated in participants who had undergone cataract surgery.Materials and methodsIn two multicenter, randomized, double-masked, parallel-group, vehicle-controlled clinical trials, 386 participants with ≥ grade 2 anterior chamber cells (≥6 cells) on the day following routine cataract surgery were treated with KPI-121 1% and 325 participants were treated with placebo (vehicle); each group was dosed BID for 2 weeks. Primary efficacy endpoints were complete resolution of ocular inflammation by slit-lamp biomicroscopy and complete resolution of subject-rated ocular pain at Days 8 and 15 with no rescue medication before Day 15. Safety assessments included adverse events (AEs), visual acuity, intraocular pressure measurements, and evaluation of ocular AEs by slit-lamp biomicroscopy and dilated ophthalmoscopy.ResultsBoth trials achieved statistical significance favoring KPI-121 1% BID for both primary efficacy endpoints. Combined data analysis showed that significantly more participants treated with KPI-121 vs vehicle achieved complete resolution of anterior chamber cells at Days 8 and 15 (P≤0.0001) and complete clearing of ocular pain at Days 4, 8, and 15 (P<0.0001). AEs were reported more frequently with vehicle than KPI-121.ConclusionKPI-121 1% ophthalmic suspension was effective in resolving postoperative ocular inflammation and pain when dosed BID for 2 weeks in patients following cataract surgery. KPI-121 was found to be safe and well tolerated in both trials.
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