Formulation and characterisation of metyrapone suppositories for the first effective long-term use in an infant with McCune-Albright syndrome-related Cushing syndrome.

OBJECTIVES: The aim of this project was to develop a rectal formulation of metyrapone suitable for application in an infant hospitalised with McCune-Albright syndrome (MAS)-related Cushing syndrome and to provide a detailed description of the formulation protocol including quality control parameters. METHODS: Suppositories with a drug load of up to 100 mg metyrapone were prepared. Mass variation, content uniformity and drug release were analysed according to the guidelines set out by the European Pharmacopoeia. Monitoring of the drug content for 6 weeks allowed for estimation of the storage stability at 2-8°C. RESULTS: A protocol for the reproducible preparation of suppositories with intended metyrapone content of 30-100 mg was established. The suppositories were well tolerated by the patient and the clinical outcome is promising. The suppository preparations complied with the regulations from the European Pharmacopoeia. Further, a stability of the rectal formulation of at least 1 month was confirmed, facilitating medication supply for home care. CONCLUSIONS: An adequate and easy to follow protocol for preparation of high-quality metyrapone suppositories, with sufficient stability for practical use and fulfilling major pharmaceutical quality parameters, was established. The protocol can be easily replicated by skilled personnel in a community pharmacy facilitating treatment of the infant in home care.

SUCCESSFUL USE OF METYRAPONE SUPPOSITORIES IN AN INFANT WITH NEONATAL CUSHING AND MCCUNE ALBRIGHT SYNDROME- A CASE REPORT.

A female toddler was diagnosed at age ten months with peripheral precocious puberty and hypercortisolism related to McCune Albright Syndrome with additional systemic complications. We present the first successful, long-term use of metyrapone as suppositories, with striking clinical and biochemical improvement and no side-effects.

A Versatile Brij-Linker for One-Step Preparation of Targeted Nanoparticles.

Background: Most frequently the functionalization of nanoparticles is hampered by time-consuming, sometimes harsh conjugation and purification procedures causing premature drug release and/or degradation. A strategy to circumvent multi-step protocols is to synthesize building blocks with different functionalities and to use mixtures thereof for nanoparticle preparation in one step. Methods: BrijS20 was converted into an amine derivative via a carbamate linkage. The Brij-amine readily reacts with pre-activated carboxyl-containing ligands such as folic acid. The structures of the building blocks were confirmed by different spectroscopic methods and their utility was assessed by one-step preparation and characterization of nanoparticles applying PLGA as a matrix polymer. Results: Nanoparticles were about 200 nm in diameter independent of the composition. Experiments with human folate expressing single cells and monolayer revealed that the nanoparticle building block Brij mediates a "stealth" effect and the Brij-amine-folate a "targeting" effect. As compared to plain nanoparticles, the stealth effect decreased the cell interaction by 13%, but the targeting effect increased the cell interaction by 45% in the monolayer. Moreover, the targeting ligand density and thus the cell association of the nanoparticles is easily fine-tuned by selection of the initial ratio of the building blocks. Conclusions: This strategy might be a first step towards the one-step preparation of nanoparticles with tailored functionalities. Relying on a non-ionic surfactant is a versatile approach as it might be extended to other hydrophobic matrix polymers and promising targeting ligands from the biotech pipeline.

Human serum albumin nanoparticles as a versatile vehicle for targeted delivery of antibiotics to combat bacterial infections.

Urinary tract infections (UTIs) are among the most common bacterial infections. Despite a wide range of therapeutic options, treatment success is compromised by the efficient mechanism of tissue colonization of uropathogenic Escherichia coli. In advanced drug delivery systems, a similar, glycan-mediated targeting mechanism may be realized by conjugating the drug to a plant lectin, like wheat germ agglutinin (WGA). We introduce a drug delivery vehicle consisting of human serum albumin as nanoparticle shell, olive oil as core component, the active pharmaceutical ingredients (API) trimethoprim and rifampicin as well as WGA to facilitate cellular internalization. When WGA was embedded into the proteinaceous particle shell, cell binding studies revealed up to 60 % higher cell binding potential. Additionally, nanoparticles showed a good efficacy against gram-negative just as against gram-positive bacteria. The combination of the promising cell-associative properties and the proven antimicrobial potential might lead to an improved efficacy of advanced treatment of UTIs.

Biocompatible polymeric microparticles serve as novel and reliable vehicles for exogenous hormone manipulations in passerines.

The administration of exogenous hormones emerged as an essential tool for field studies in endocrinology. However, working with wild animals remains challenging, because under field conditions not every available method meets the necessary requirements. Achieving a sustained elevation in hormone levels, while simultaneously minimising handling time and invasiveness of the procedure is a difficult task in field endocrinology. Facing this challenge, we have investigated the suitability of biocompatible polymeric microparticles, a novel method for drug-administration, as a tool to manipulate hormones in small songbirds. We chose the insulin-like growth factor-1 (IGF-1) as target hormone, because it receives great interest from the research community due to its important role in shaping life-history traits. Moreover, its short half-life and hydrophilic properties imply a major challenge in finding a suitable method to achieve a sustained, systemic long-term release. To study the release kinetics, we injected either IGF-1 loaded polylactic-co-glycolic acid (PLGA) microparticles or dispersion medium (control group) in the skin pocket of the interscapular region of captive bearded reedlings (Panurus biarmicus). We collected blood samples for 7 consecutive days plus an additional sampling period after two weeks and complemented these with an in vitro experiment. Our results show that in vitro, PLGA microparticles allowed a stable IGF-1 release for more than 15 days, following a burst release at the beginning of the measurement. In vivo, the initial burst was followed by a drop to still elevated levels in circulating IGF-1 until the effect vanished by 16 days post-treatment. This study is the first to describe the use of PLGA-microparticles as a novel tool for exogenous hormone administration in a small passerine. We suggest that this method is highly suitable to achieve the systemic long-term release of hydrophilic hormones with short half-life and reduces overall handling time, as it requires only one subcutaneous injection.

LogP of N-acyl-gemcitabine and lectin-corona emerge as key parameters in nanoparticulate intravesical cancer therapy.

After surgical removal of the tumour tissue, bladder cancer is treated by intravesical instillation of cytotoxic drugs such as gemcitabine. Gemcitabine, however, is highly hydrophilic and possesses a short half-life due to fast enzymatic deamination. Additionally, continuous dilution by urine, a hardly permeable urothelial barrier and rapid excretion by urination make therapy difficult. To modify lipophilicity of the drug, N-acyl-gemcitabine derivatives with quite different solubility and logP were synthesized, purified and characterized. The loading of PLGA nanoparticles with the N-acyl-gemcitabine derivatives followed by release in artificial urine, revealed that the drug content increases but the subsequent release decreases with lipophilicity. Additionally, acylation increased cytotoxicity and opened passive diffusion as an additional pathway into cancer cells. To address physiological constraints, the surface of the monodisperse nanoparticles was grafted with bioadhesive wheat germ agglutinin. Cytoadhesion to artificial bladder cancer tissue and even uptake into the cells as indicated by microscopic imaging are expected to prolong the retention time in the bladder cavity as well as to promote uptake into the cells. By using N-caprylic-gemcitabine as most appropriate gemcitabine-derivative for drug loading and making use of the bioadhesive characteristics of wheat germ agglutinin for grafting the corona of PLGA-nanoparticles, an innovative strategy towards smart drug delivery for instillative therapy of bladder cancer is proposed.