Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release

Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed

Simultaneous determination of ethinyl estradiol and drospirenone in oral contraceptive by high performance liquid chromatography

A simple, rapid, economical and reliable high performance liquid chromatographic method has been developed and successfully applied in simultaneous determination of ethinyl estradiol and drospirenone in coated tablets. The HPLC method was performed on a LiChroCART® 100RP column (125x4 mm i.d., 5 µm) with acetonitrile:water 50:50 (v/v) as mobile phase, pumped at a flow rate of 1.0 mL.min-1. The fluorescence detection for ethinyl estradiol was made at λex= 280 nm and λem= 310 nm and a UV detection for drospirenone was made at 200 nm. The elution time for ethinyl estradiol and drospirenone were 4.0 and 5.7 min, respectively. The method was validated in accordance to USP 34 guidelines. The proposed HPLC method presented advantages over reported methods and is suitable for quality control assays of ethinyl estradiol and drospirenone in coated tablets

Transfer of drospirenone to breast milk after a single oral administration of 3 mg drospirenone +30 mu g ethinylestradiol to healthy lactating women

Drospirenone (DPSP) is a synthetic progestogen which has been developed in combination with ethinylestradiol (EE) for use as an oral contraceptive (Yasmin(R), Schering AG, Berlin, Germany). The pharmacokinetic characteristics ofDRSP were evaluated in serum and breast milk from lactating women who received a single oral dose of 3 mg DRSP + 30 mug EE, to determine the fraction of the dose of DRSP which transfers to breast milk. Nine healthy, lactating women were included into the present study and pharmacokinetic data were obtained from six participants. The maximum DRSP concentrations (data given as mean standard deviation) were reached on average 2.5 +/- 1.2 and 2.8 +/- 1.3 h in serum and breast milk, respectively after oral administration of 3 mg DRSP + 30 mug EE, and amounted on average to 30.8 +/- 14.4 and 13.5 +/- 11.7 ng DRSP/ml in serum and breast milk. The mean breast milk versus serum concentration ratios of DPSP increased from 0.16 to 0.57 within 2 h after dosing and decreased to 0.16 after 24 h. The average ratio of AUC(0-48 h) , values in breast milk versus serum was 0.23 +/- 0.09. The mean DRSP concentration in breast milk over the 24-h period after dosing was 3.7 +/- 1.9 ng/ml. The amount of DRSP measured to be transferred into breast milk in the six women participating in the present study was, on average, 635 ng (range 256.2-1357.9 ng) within 24 h, corresponding to about 0.02% of the maternal dose. Based on the average concentration of the drug in breast milk over 24 h and assuming a daily ingestion of approximately 800 ml breast milk, the daily dose that reaches an infant via breast milk is estimated to be approximately 3 mug DPSP. The subjective and objective tolerances of 3 mg DRSP + 30 mug EE were good, with no adverse events reported

Ueberpruefung eines Pathogenese-Konzepts bei Demenzen und Einordnung dieser Krankheiten in ein Schema pathologischer Proteine Abschlussbericht

Available from TIB Hannover: DtF QN1(46,7) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

EE-drospirenone-levomefolate calcium versus EE-drospirenone + folic acid: folate status during 24 weeks of treatment and over 20 weeks following treatment cessation

Konstanze Diefenbach,1 Dietmar Trummer,1 Frank Ebert,1 Michael Lissy,2 Manuela Koch,2 Beate Rohde,1 Hartmut Blode3 1Bayer HealthCare Pharmaceuticals, Berlin, Germany; 2Nuvisan GmbH, Neu-Ulm, Germany; 3Bayer HealthCare Pharmaceuticals Global R&D Center, Beijing, People's Republic of China Background: Adequate folate supplementation in the periconceptional phase is recommended to reduce the risk of neural tube defects. Oral contraceptives may provide a reasonable delivery vehicle for folate supplementation before conception in women of childbearing potential. This study aimed to demonstrate that a fixed-dose combination of an oral contraceptive and levomefolate calcium leads to sustainable improvements in folate status compared with an oral contraceptive + folic acid. Methods: This was a double-blind, randomized, parallel-group study in which 172 healthy women aged 18–40 years received ethinylestradiol (EE)-drospirenone-levomefolate calcium or EE-drospirenone + folic acid for 24 weeks (invasion phase), and EE-drospirenone for an additional 20 weeks (folate elimination phase). The main objective of the invasion phase was to examine the area under the folate concentration time-curve for plasma and red blood cell (RBC) folate, while the main objective of the elimination phase was to determine the duration of time for which RBC folate concentration remained ≥ 906 nmol/L after cessation of EE-drospirenone-levomefolate calcium. Results: Mean concentration-time curves for plasma folate, RBC folate, and homocysteine were comparable between treatment groups during both study phases. During the invasion phase, plasma and RBC folate concentrations increased and approached steady-state after about 8 weeks (plasma) or 24 weeks (RBC). After cessation of treatment with levomefolate calcium, folate concentrations decreased slowly. The median time to RBC folate concentrations falling below 906 nmol/L was 10 weeks (95% confidence interval 8–12 weeks) after cessation of EE-drospirenone-levomefolate calcium treatment. Plasma and RBC folate levels remained above baseline values in 41.3% and 89.3% of women, respectively, at the end of the 20-week elimination phase. Conclusion: Improvements in folate status were comparable between EE-drospirenone-levomefolate calcium and EE-drospirenone + folic acid. Plasma and RBC folate levels remained elevated for several months following cessation of treatment with EE-drospirenone-levomefolate calcium. Keywords: drospirenone, ethinylestradiol, folic acid, levomefolate calcium, neural tube defect, oral contraceptio

Pharmacokinetics and pharmacodynamics of drospirenone-estradiol combination hormone therapy product coadministered with hydrochlorothiazide in hypertensive postmenopausal women

The effects of combination hormone therapy of drospirenone (DRSP), a novel progestin with antialdosterone properties, and 17beta-estradiol (E2) on hydrochlorothiazide (HCTZ) pharmacokinetics/pharmacodynamics versus placebo were investigated in a double-blind, placebo-controlled, crossover study. Thirty-six postmenopausal women with stage 1 hypertension maintained on 25 mg of HCTZ once daily were randomized to receive either 3 mg of DRSP/1 mg of E2 or placebo once daily for 4 weeks. Plasma HCTZ, serum DRSP, E2, potassium, aldosterone, and plasma renin activity were determined at baseline and after 4 weeks. Results showed that the combination of DRSP/E2 plus 25 mg of HCTZ is safe and well tolerated in hypertensive postmenopausal women. The pharmacokinetics of HCTZ were not affected by coadministration of DRSP/E2. The geometric mean ratios and 90% confidence intervals ([HCTZ + DRSP/E2]/[HCTZ + placebo]) for HCTZ (a) area under the serum/plasma concentration-time curve from 0 to 24 hours and (b) maximum plasma concentration were 101 (90.7, 112) and 103 (92.8, 115), respectively. In the HCTZ + DRSP/E2 group, serum potassium, aldosterone, and plasma renin activity all increased in a manner marginally consistent with a beneficial antialdosterone effect, counteracting the HCTZ-induced potassium loss and lowering both systolic and diastolic blood pressure. No dose adjustment is required when DRSP/E2 is added to antihypertensive therapy with HCTZ in hypertensive postmenopausal women