Anthony Michael Campeta
Pfizer
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Publication
Featured researches published by Anthony Michael Campeta.
Journal of Pharmaceutical Sciences | 2010
Anthony Michael Campeta; Brian P. Chekal; Yuriy A. Abramov; Paul Meenan; Mark J. Henson; Bing Shi; Robert A. Singer; Keith R. Horspool
Elucidation of the most stable form of an active pharmaceutical ingredient (API) is a critical step in the development process. Polymorph screening for an API with a complex polymorphic profile can present a significant challenge. The presented case illustrates an extensively polymorphic compound with an additional propensity for forming stable solvates. In all, 5 anhydrous forms and 66 solvated forms have been discovered. After early polymorph screening using common techniques yielded mostly solvates and failed to uncover several key anhydrous forms, it became necessary to devise new approaches based on an advanced understanding of crystal structure and conformational relationships between forms. With the aid of this analysis, two screening approaches were devised which targeted high-temperature desolvation as a means to increase conformational populations and enhance overall probability of anhydrous form production. Application of these targeted approaches, comprising over 100 experiments, produced only the known anhydrous forms, without appearance of any new forms. The development of these screens was a critical and alternative approach to circumvent solvation issues associated with more conventional screening methods. The results provided confidence that the current development form was the most stable polymorph, with a low likelihood for the existence of a more-stable anhydrous form.
Bioorganic & Medicinal Chemistry | 2003
Philip A. Carpino; Bruce Allen Lefker; Steven M. Toler; Lydia Codetta Pan; John R. Hadcock; Ewell R. Cook; Joseph DiBrino; Anthony Michael Campeta; Shari L. DeNinno; Kristin L. Chidsey-Frink; William A. Hada; John Inthavongsay; F.Michael Mangano; Michelle A. Mullins; David F. Nickerson; Oicheng Ng; C.M. Pirie; John A. Ragan; Colin R. Rose; David A. Tess; Ann S. Wright; Li Yu; Michael P. Zawistoski; Paul DaSilva-Jardine; Theresa C. Wilson; David Duane Thompson
Novel pyrazolinone-piperidine dipeptide derivatives were synthesized and evaluated as growth hormone secretagogues (GHSs). Two analogues, capromorelin (5, CP-424391-18, hGHS-R1a K(i)=7 nM, rat pituicyte EC(50)=3 nM) and the des-methyl analogue 5c (hGHS-R1a K(i)=17 nM, rat pituicyte EC(50)=3 nM), increased plasma GH levels in an anesthesized rat model, with ED(50) values less than 0.05 mg/kg iv. Capromorelin showed enhanced intestinal absorption in rodent models and exhibited superior pharmacokinetic properties, including high bioavailabilities in two animal species [F(rat)=65%, F(dog)=44%]. This short-duration GHS was orally active in canine models and was selected as a development candidate for the treatment of musculoskeletal frailty in elderly adults.
Journal of Pharmaceutical Sciences | 2011
Brian Samas; Christopher Seadeek; Anthony Michael Campeta; Brian P. Chekal
There are two major challenges in developing a solid form: (1) identifying the thermodynamically stable form and (2) determining the method used to crystallize that form. Often experiments performed to address these challenges have different objectives and use separate experimental techniques. The thermodynamically stable form is usually found on small scale, utilizing slurries or crystallizations. Subsequently, a crystallization process is developed to purge impurities and to increase yield and these experiments are typically conducted on medium to large scale (greater than 10 g). Axitinib, a research compound for the treatment of cancer, forms solvates in most solvents to which it is exposed, presenting a problem in discovering and making a desirable anhydrous phase. A method has been developed that will give the best chance of making a thermodynamic stable form of the anhydrous material, necessarily not a desolvated form. This approach relies on solvent mediated transformation (thermodynamic control), rather than crystallization or solid-to-solid phase desolvation (generally kinetic control). Experimental conditions (a desolvation window) to produce an anhydrous solid form for this compound that shows predominance for solvate formation is detailed.
Journal of Physical Organic Chemistry | 1999
Anthony Michael Campeta; Franco Lombardo; Thomas R. Sharp; George J. Horan; Diane M. Rescek
A combination of high-performance liquid chromatography (HPLC)–mass spectrometry and 1H and 13C NMR spectroscopy was utilized to characterize the photodecay products of droloxifene, a potent new estrogen receptor agonist. Structurally similar to tamoxifen, droloxifene demonstrates a complex and unique decay scheme, including the formation of two naphthalene derivatives which were unexpected decay products and previously unreported for this class of compound. Elucidation of the decay products was assisted by the use of computational chemistry, namely by correlating simulated UV spectra and aqueous solvation free energies with actual UV spectra and HPLC retention data. In addition to describing the photodecay scheme of droloxifene, the present work demonstrates the utility of computational chemistry in providing support for the identification of unknown compounds. Copyright
Journal of Medicinal Chemistry | 1996
Ralph P. Robinson; Lawrence A. Reiter; Wayne E. Barth; Anthony Michael Campeta; Kelvin Cooper; Brian J. Cronin; Rosalina Destito; Kathleen M. Donahue; Fred C. Falkner; Eugene F. Fiese; Diane L. Johnson; Alexander V. Kuperman; Theodore E. Liston; Deborah Malloy; John J. Martin; David Young Mitchell; Frank W. Rusek; Sheri L. Shamblin; Charles F. Wright
Organic Process Research & Development | 2009
Brian P. Chekal; Anthony Michael Campeta; Yuriy A. Abramov; Neil Feeder; Paul P. Glynn; Robert W. McLaughlin; Paul Meenan; Robert A. Singer
Archive | 2005
Anthony Michael Campeta; Joseph F. Krzyzaniak; Jason Albert Leonard
Archive | 1998
Anthony Michael Campeta
Archive | 2008
Anthony Michael Campeta; Brian P. Chekal; Robert William Mclaughling; Robert A. Singer
Archive | 2011
Patricia Ann Basford; Anthony Michael Campeta; Adam T. Gillmore; Matthew Cameron Jones; Eleftherios Kougoulos; Suman Luthra; Robert Walton