1:2 Inclusion complex progesterone/HPBCD studied by Raman and NMR spectroscopy

Complexes between Progesterone (P) and β-cyclodextrin (BCD) to obtain water soluble formulations are widely known; since hydroxypropyl β-cyclodextrin (HPBCD) displays higher water solubility (48% p/v), we started experiments to achieve a better solubilization of the hormone, to obtain up to 50 mg/ml progesterone concentration in physiological solution, to formulate a suitable dosage form for progesterone therapy. We developed a production process in which the residual BCD (commercial HPBCD contains up to 0.8 % of unreacted material) is preliminarly separated by the formation of a poorly soluble complex. The stoichiometry and stability constant of the desired soluble complex were calculated by phase/solubility study. DSC and X-Ray analysis confirmed the absence of crystalline P in the final freeze-dried powder. The structural evaluation by spectroscopic analysis (Raman, FTIR and NMR) confirms the presence of an inclusion complex with a stoichiometry guest/host 1:2. The Raman spectrum of P shows tree sharp signals at 1616, 1664 and 1669 cm-1 due to the two carbonyls in position 3 and 20 of the steroid structure. HPBCD alone does not show signals in the considered area. P/HPBCD complex show a broad main signal at 1657 cm-1with a minor signal at 1691 cm-1 This change in the spectrum indicates the inclusion of the progesterone involving both rings A and D of the steroid structure. This idea was also confirmed by FT-IR spectroscopy (right). NMR experiment shows shifts of signals attributed to P protons 4, 18,19 and 21 indicating again a involvement of rings A and D in the inclusion complex (left)

A neonate with cyanosis and tortuous great arteries.

surgical repair of complex aortic arch disease in newbor

New injectable formulation containing water soluble Progesterone-Hydroxypropyl-beta-cyclodextrin complex

Progesterone (P) is a natural hormone used as a drug to control reproductive function and for postmenopausal therapy. Oral and vaginal routes display low bioavailability and, in addition, oral route has a limited usefulness, because of P short half-life and extensive degradation after absorption. Therefore the injection route should be the preferred choice, since the oily solution and the aqueous suspension allow only intramuscolar administration. This encourages the research of new injectable pharmaceutical form with increase of the patient compliance. Water-soluble P formulations represent a suitable solution, because they could be administered also by subcutaneous route, therefore allowing auto medication and less pain during the treatment is expected. Pitha et al. described the use of Cyclodextrins to increase the water solubility of Progesterone (P), through the formation of an inclusion complex to obtain a water soluble formulation (1). Also other authors, using different physico-chemical methods (2, 3, 4), reported experimental evidences of the inclusion complex formation between P and b-cyclodextrin and derivatives. Among the cyclodextrins tested hydroxypropyl-b-cyclodextrin (HPBCD) is a suitable choice for formulations containing therapeutic concentration of P. The therapeutic dosage of P by injection varies from 5 to 200 mg. as a function of the specific pathology (5). HPBCD, displaying high water solubility (48% p/v), allows solubilisation of large quantity of P. Considering the formation of a 1:2 complex, it is possible to obtain solutions up to 50 mg/ml P, which is a considerable dosage in the progesterone therapy. In the development of P/HPBCD complex we observed the formation of a light precipitate under stability ICH conditions. Choi et al (4) and also by Pitha et al (1) noticed the precipitate formation, but its chemical structure was not elucidated. This work describes a method to obtain a P/HPBCD without insoluble particles, the physico-chemical characterization of the precipitate and of the purified inclusion complex

ATR/Raman and fractal characterization of HPBCD/progesterone complex solid particles

PURPOSE: Characterization of hydroxypropyl-beta-cyclodextrin/progesterone (HPBCD/P) complex solid particles obtained from an aqueous solution, by three different technological processes, with the aim of preparing ready-to-dissolve powders for injectable as well as solid oral formulations in progestinic therapy. METHODS: HPBCD/P complex in the 2:1 molar ratio was prepared in aqueous solution and obtained as dry solid particles by freeze-drying, by spray-drying and by fluid-bed evaporation of the solvent. The particles were characterized by mu-FT-IR, mu-Raman and X-ray spectroscopy, by thermal analysis (differential scanning calorimetry-DSC and thermogravimetry-TGA), by Karl Fischer (KF) titration, by image and fractal analysis and by BET specific surface area analysis. The structure of the complex was also defined by comparison of FT-IR and Raman spectra of progesterone with those of pregnenolone and testosterone, structurally related. Dissolution tests were also performed. RESULTS: Powders of the complex obtained by the three different methods are different in size and shape. Particles obtained by freeze-drying are flat and angular, irregularly shaped without any relation to known geometrical solid figures. Particles obtained by spray-drying are spherically shaped and display a very small size (5-10 microm), with evident deformations and depression of the external surface, due to the rapid evaporation of the solvent. Particles obtained by fluid bed technique have intermediate sizes, display a tri-dimensional structure and irregular surface, with small and rounded protuberances. Fractal dimension of the particle contour was found close to one unit for the microspheres obtained by spray-drying. FT-IR and Raman spectra confirm the occurrence of the complexation by the shift of representative bands of the two carbonyl groups in positions 3 and 20 of the complexed progesterone. X-ray diffractograms indicate the amorphous nature of all the types of particles, also suggested by the absence of any melting peak of the drug in DSC thermograms. The samples contain different amounts of humidity: particles obtained by fluid-bed method demonstrated non-porous in BET analysis. Dissolution of different types of particles is complete after 3 min and only negligible differences could be appreciated among the three powders. CONCLUSIONS: - mu-FT-IR, mu-Raman and X-ray spectroscopy, and the dissolution test did not reveal defined differences among the three different types of particles, confirming occurrence of the complex in the solid state. The spherical shape, the very small size and the low value of the contour fractal dimension allows better technological performance of the particles obtained by spray-drying: this drying process appears the most promising one to prepare dry particles of the HPBCD/P complex, in view of its formulation in the fast preparation of extemporaneous injectable solutions and solid oral formulations intended for sublingual delivery

Aortic root physiology late after a "perfect" ross operation: magnetic resonance imaging study of three operative techniques.

In order to define physiological properties of the autograft root, magnetic resonance imaging (MRI) findings relative to three different operative techniques were compared with those of control subjects. Twenty-three patients, 18/5 M/F, aged 32 \ub1 9 years, underwent MRI assessment of the aortic root. Patients with normally functioning autograft valve and at least 4 years of follow-up (average 5.6 \ub1 1.9, range 4-10 years) were selected for each technique: six subcoronary (Group 1), nine inclusion (Group 2), and eight freestanding root (Group 3). Results were compared among patient groups and with seven control subjects, 6/1 M/F, aged 30 \ub1 2 years (P = ns). Morphological and functional properties were defined using transverse and paracoronal views, during systole and diastole. Mean aortic size in each group was greater than control, except for the LV-aortic junction and the sinus of Valsalva in Group 1 (26 \ub1 5 vs. 23 \ub1 3 mm, P = 0.2 and 33 \ub1 6 vs. 30 \ub1 5 mm, P = 0.3). Aortic valve plane rotation (P = 0.02) and root dilatation (P = 0.02) were more common in Group 3. Altered valve opening dynamics and asymmetrical aortic flow profile were also more common in Group 2 (P = 0.03) and Group 3 (P = 0.04). Distensibility was significantly reduced at sinus level in Group 2 and 3 compared with control (4.1 \ub1 3.5% and 3.6 \ub1 4.4% vs. 9.0 \ub1 4.7%, P = 0.03). Asymmetrical aortic flow profile was more common in patients with aortic dilatation (P = 0.05) and with severely reduced (<4%) root elasticity (P = 0.06). Among the three techniques, only subcoronary grafting allows preservation of physiological autograft valve dynamics, aortic flow and distensibility, at all root levels, late after operation. These findings may have relevant implications in the selection of the ideal Ross technique

Reparative surgery of the pulmonary autograft: experience with Ross reoperations.

OBJECTIVE:Autograft valve and root pathology is the leading cause of Ross procedure failure. To define risk and outcome of autograft valve/root repair at reoperation, a 17-year experience was analysed.METHODS:One hundred and thirty-two consecutive late survivors underwent cross-sectional clinical and echocardiographic examination on average 10.8 \ub1 14.7 years (range 0.4-17) after Ross procedure. Study endpoints were hospital and late morbidity, freedom from autograft reoperation, freedom from root/valve replacement and functional outcome after valve/root repair.RESULTS:Twenty-seven (20%) patients underwent 33 cardiac reoperations, the first on average 7.7 \ub1 4.5 years (range 0.08-16.2) after Ross operation. Nineteen had undergone root replacement, 5 inclusion cylinder and 3 subcoronary grafting. Indication was root pathology in 17 (63%) patients and isolated valve in 10. Surgery consisted in valve repair/sparing in 17 patients and valve/root replacement in 10, with no hospital mortality. Freedom from any autograft valve/root reoperation was 74 \ub1 5% at 15 years. No patient with valve/root replacement required second reoperation. Instead, 6/17 (35%) patients having autograft valve repair/sparing and followed for 4.2 \ub1 2.9 years (range 0.3-10.8) required re-repair/AVR, while 11 present mild AI or less. Freedom from autograft valve/root replacement was 83 \ub1 5% at 15 years. At multivariate analysis, predictors of reoperation were age at Ross (P = 0.002) and use of root technique (P = 0.049). Failure of autograft valve repair/sparing was associated with isolated valve pathology (P = 0.014) and earlier reoperation (P = 0.002). Pre-repair autograft insufficiency was significant at univariate analysis only (P = 0.01).CONCLUSIONS:Autograft reoperation carries negligible hospital risk. Pulmonary valve sparing or repair is feasible in half of patients with Ross failure. Concomitant root remodelling and absence of preoperative severe valve dysfunction predict successful and durable repair