Simultaneous quantitation of multiple contraceptive hormones in human serum by LC-MS/MS.

OBJECTIVE: The objective was to develop a method to simultaneously quantify five commonly used hormonal contraceptives (HCs) and two endogenous sex steroids by liquid chromatography-tandem triple quadrupole mass spectrometry (LC-MS/MS) and apply this method to human serum samples. STUDY DESIGN: We developed a method to simultaneously analyze ethinyl estradiol (EE2), etonogestrel (ENG), levonorgestrel (LNG), medroxyprogesterone acetate (MPA) and norethisterone (NET), along with estradiol (E2) and progesterone (P4), in human serum for a Shimadzu Nexera-LCMS-8050 LC-MS/MS platform. We analyzed serum collected from women self-reporting use of oral contraceptives, contraceptive implants or injectable contraceptives (n=14) and normally cycling women using no HC (n=15) as well as pooled samples from women administered various HCs (ENG, n=6; LNG, n=14; MPA, n=7; NET, n=5). RESULTS: Limits of quantitation were 0.010ng/mL for E2, EE2 and P4; 0.020ng/mL for ENG, LNG and MPA; and 0.040ng/mL for NET. Precisions for all assays, as indicated by coefficient of variation, were less than or equal to 12.1%. Accuracies for all assays were in the range of 95%-108%. Endogenous hormone values obtained from analysis of human serum samples are in agreement with levels previously reported in the literature for normally cycling women as well as for women taking the appropriate HC. CONCLUSIONS: We have developed a robust, accurate and sensitive method for simultaneously analyzing commonly used contraceptive steroids and endogenous sex steroids in human serum. IMPLICATIONS: This analytical method can be used for quantitating contraceptive steroid levels in women for monitoring systemic exposure to determine drug interactions, nonadherence, misreporting and proper dosing.

Corneal graft survival and intraocular pressure control in coexisting penetrating keratoplasty and pars plana Ahmed Glaucoma Valves.

PURPOSE: To evaluate corneal graft survival and intraocular pressure (IOP) control after penetrating keratoplasty (PK) and pars plana Ahmed Glaucoma Valve (AGV) implantation among patients with coexisting glaucoma and corneal disease. METHODS: Retrospective chart review at an institution of 25 eyes (24 patients) that received PK and pars plana AGV. RESULTS: The mean postoperative follow-up was 23 months (range, 2-106 months). Survival of the grafts was 89% (16 of 18 eyes) at 1 year and 63% (5 of 8) at 2 years. IOP control was 78% (15 of 19) at 1 year and 44% (4 of 9) at 2 years. By Kaplan-Meier analysis, the 50% probability of sustained graft clarity occurred at 28 months and that of sustained IOP control at 24 months. By last follow-up, best-corrected visual acuity had improved by at least 1 line in 52% (13 of 25) of eyes compared with preoperative values. Preoperative factors, including peripheral anterior synechiae, were not found to be associated with graft survival, IOP control, or visual acuity at 1 year. CONCLUSION: Pars plana AGV can successfully control IOP in PK patients in the short and intermediate terms, but graft clarity and IOP control diminish over time. Graft decompensation, when it did occur, likely reflects the associated ocular morbidity and clinical complexity of this circumscribed cohort of eyes.

Hydrodynamic chromatography for the size classification of micron and sub-micron sized packing materials.

Hydrodynamic chromatography (HDC) was used as a size classification and purification method for porous bridged ethyl hybrid (BEH) packing materials (particles) in the micron to sub-micron range. Using packed column HDC, a batch of particles with size 0.76+/-0.26microm was fractionated to yield classified material of 1.05+/-0.16microm, reducing the relative standard deviation from 33% to 15%. Subsequent chromatographic evaluation of this packing material showed significant improvement in column performance and decrease in flow resistance over the unclassified material. Comparing a column packed with the classified versus non-classified material, the effective flow resistance of the two columns was decreased by 58% and the minimum HETP for the packing material was improved from 4 to 2.5microm.