Ibuprofen nanocrystals developed by 22 factorial design experiment: A new approach for poorly water-soluble drugs.

The reduction of the particle size of drugs of pharmaceutical interest down to the nano-sized range has dramatically changed their physicochemical properties. The greatest disadvantage of nanocrystals is their inherent instability, due to the risk of crystal growth. Thus, the selection of an appropriate stabilizer is crucial to obtain long-term physicochemically stable nanocrystals. High pressure homogenization has enormous advantages, including the possibility of scaling up, lack of organic solvents and the production of small particles diameter with low polydispersity index. The sequential use of high shear homogenization followed by high pressure homogenization, can modulate nanoparticles' size for different administration routes. The present study focuses on the optimization of the production process of two formulations composed of different surfactants produced by High Shear Homogenization followed by hot High Pressure Homogenization. To build up the surface response charts, a 22 full factorial design experiment, based on 2 independent variables, was used to develop optimized formulations. The effects of the production process on the mean particle size and polydispersity index were evaluated. The best ibuprofen nanocrystal formulations were obtained using 0.20% Tween 80 and 1.20% PVP K30 (F1) and 0.20% Tween 80 and 1.20% Span 80 (F2). The estimation of the long-term stability of the aqueous suspensions of ibuprofen nanocrystals was studied using the LUMISizer. The calculated instability index suggests that F1 was more stable when stored at 4 °C and 22 °C, whereas F2 was shown to be more stable when freshly prepared.

Bone health in patients with prostate cancer.

CONTEXT: In patients with prostate cancer, bone health is compromised by advanced age at diagnosis, androgen suppression treatments and the developmentofbone metastases. In this paper the medical literature is reviewed in order to update the state of the art on their incidence, prevention and management. EVIDENCE ACQUISITION: A literature review about bone involvement in patients with prostate cancer in different clinical settings is performed. SYNTHESIS OF THE EVIDENCE: Decreased bone mineral density is higher in patients diagnosed of prostate cancer before starting treatment than in healthy men with the same age. During the first year of treatment, a severe loss bone density is reported due to androgen suppression therapy. From then on, loss bone density seems to slow down, persisting at long-term. It is important to know the starting point and the dynamics of loss bone in order to prevent its progression. The skeletal events have an important impact on quality of life in patients with prostate cancer. Both Denosumab and Zoledronic Acid have proven effective in reducing loss bone. CONCLUSIONS: The prevention and management of bone involvement in patients with prostate cancer is critical to quality of life in these patients and requires an individualized approach. Before starting a prolonged androgen deprivation, baseline risk of fracture should be evaluated in order to adopt the proper protective measures. In patients with metastases, early treatments reducing the risk of bone events should be taken into account.

Phase II trial of short-term neoadjuvant docetaxel and complete androgen blockade in high-risk prostate cancer.

BACKGROUND: The low probability of curing high-risk prostate cancer (PC) with local therapy suggests the need to study modality of therapeutic approaches. To this end, a prospective phase II trial of neoadjuvant docetaxel (D) and complete androgen blockade (CAB) was carried out in high-risk PC patients. The primary end point was to detect at least 10% of pCRs after chemohormonal treatment. METHODS: Patients with T1c-T2 clinical stage with prostate-specific antigen (PSA) >20 ng ml(-1) and/or Gleason score >or=7 (4+3) and T3 were included. Treatment consisted of three cycles of D 36 mg m(-2) on days 1, 8 and 15 every 28 days concomitant with CAB, followed by radical prostatectomy (RP). RESULTS: A total of 57 patients were included. Clinical stage was T1c, 11 patients (19.3%); T2, 30 (52.6%) and T3, 16 (28%) patients. Gleason score was >or=7 (4+3) in 44 (77%) patients and PSA >20 ng ml(-1) in 15 (26%) patients. Treatment was well tolerated with 51 (89.9%) patients completing neoadjuvant therapy together with RP. The rate of pCR was 6% (three patients). Three (6%) additional patients had microscopic residual tumour (near pCR) in prostate specimen. With a median follow-up of 35 months, 18 (31.6%) patients presented PSA relapse. CONCLUSION: Short-term neoadjuvant D and CAB induced a 6% pCR rate, which is close to what would be expected with ADT alone. The combination was generally well tolerated.

Molecular modelling and 1H-NMR: ultimate tools for the investigation of tolbutamide: beta-cyclodextrin and tolbutamide: hydroxypropyl-beta-cyclodextrin complexes.

A structural study of the inclusion compound of tolbutamide (TBM) with beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was attempted by means of 1H-nuclear magnetic resonance (1H-NMR) experiments and computer molecular modelling. To establish the stoichiometry and stability constant of the beta-CD:TBM complex, the continuous variation method was used. The presence of true inclusion complexes between TBM and beta-CD or HP-beta-CD in solution was clearly evidenced by the 1H-NMR technique. Changes in chemical shifts of H-3 and H-5 protons, located inside the CD cavity, associated with variations in the chemical shifts of TBM aromatic protons provided clear evidence of inclusion complexation, suggesting that the phenyl moiety of the drug molecule was included in the hydrophobic cavity of CDs. This view was further supported by the observation of intermolecular NOEs between TBM and beta-CD and by the aid of a molecular modelling program, which established the most probable structure of the complex. The molecular graphic computation confirmed that the minimum energy, positioning TBM relative to beta-CD, occurs when the aromatic ring of TBM is included within the beta-CD cavity by its wider side, leaving the aliphatic chain externally, which is in good agreement with the results of 1H-NMR studies.