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PubMedDate not supplied

Market access for biopharmaceuticals: new challenges.

Biotechnology firms face new challenges as biologics account for an increasing share of product approvals and pipelines and their high costs are under scrutiny by regulators, employers, and consumers. Although the first generation of biologics often targeted niche markets with little impact on payers' total costs, the current product wave addresses larger populations. To meet the needs of all stakeholders, manufacturers must adopt an evidence-based approach including three principles: demonstration of clinical and economic value, price evolution according to market conditions (from orphan diseases to large areas such as diabetes), and an early timetable integrating clinical and economic endpoints.

Biopharmaceutics↗
PubMed2003

Manipulating the reversible aggregation of protein hormones in secretory granules: potential impact on biopharmaceutical development.

Neuroendocrine cells and other secretory cell types are able to store secretory proteins in a concentrated form for extended periods until the release of large quantities of protein is triggered. The proteins are stored in dense core secretory granules. The dense cores of these granules are made up of large, insoluble aggregates that form by self-association. These aggregates solubilise rapidly into monomeric proteins in their native conformations when released from the cells by exocytosis of secretory granules. Formation of aggregates is an early event in secretory granule formation in at least some cell types. The function of secretory granules containing protein aggregates varies, depending upon the contents. This may occur because recognition of an aspect, such as a surface motif, of the aggregate facilitates correct assembly of the membrane proteins necessary for transport and exocytosis of the granules. Understanding the principles necessary for aggregation of protein hormones may help in the formulation of proteins for clinical use. Formation of aggregates of human prolactin has been investigated both in cells and in solution. In cells, the aggregation of human prolactin requires a mildly acidic pH, and is slowed in the presence of a membrane-permeable chelator of zinc. In solution, the aggregation of human prolactin at mildly acidic pH and physiological concentrations of Zn(2+) resembles that which occurs in cells if the reaction is performed with macromolecular crowding, which will mimic the conditions in cells. The factors causing protein aggregation and the extent to which aggregation plays a role in secretory granule formation are likely to vary with the protein and cell type. Further understanding of the principles involved in forming these aggregates that readily disassociate may enhance the ability to formulate protein preparations. Knowledge of the exact residues involved in the protein : protein interfaces in the aggregates of secretory granule proteins may lead to the ability to use small molecules to interfere with self-association and to regulate the storage of secretory granule proteins.

Biopharmaceutics↗
PubMed2000

Biopharmaceutical powders: particle formation and formulation considerations.

It is well known that protein/peptide-based drug formulations are more stable in the solid state than in the liquid state, thereby offering stability advantages in ambient temperature storage, product shipping/distribution, and long-term shelf life. Novel powder-based drug delivery systems recently emerging for applications in sustained release, inhalation, intradermal delivery, etc, add more value to protein solid dosage forms. Despite great research interests in understanding the drying effects on protein stability and a large collection of publications focusing on this area, systematic accounts of powder formation techniques are lacking. This review is to summarize a number of methods currently available for protein powder preparation. Some are common methods such as lyophilization, spray drying, pulverization, and precipitation, and some methods are more recently developed such as supercritical fluid precipitation, spray-freeze drying, fluidized-bed spray coating and emulsion precipitation. In addition to examining the individual process effect on protein stability that is always the focus of formulation scientists, this review also likes to evaluate each method from a more practical sense in terms of process versatility and scalability. The conclusion is that each method has its own advantages and the use of a method is formulation and application specific. With the understanding of the principles and advantages of these methods, it can benefit our choice on selecting appropriate techniques for preparing a desired protein powder formulation for specific applications.

Biopharmaceutics↗
PubMed1981

The importance of biopharmaceutic considerations in biological assays of LHRH and its analogs.

The choice of vehicle, route of administration and actual biological end-point utilized to measure the potency of LHRH analogs can have marked effects on the results of such studies. The activities of LHRH and an analog (D-TRP6,Pro9-NEt-LHRH) suspended in two vehicles were evaluated in two different biological tests including induction of ovulation in androgen sterilized rats and stimulation of uterine growth in immature mice. Our data clearly demonstrate that variables inherent in bioassays used to study LHRH analogs must be controlled if valid conclusions are to be made regarding the relative pharmacological activity and potency of these peptides.

Androgens↗
PubMed1999

Preparation and biopharmaceutical evaluation of nitrofurantoin loaded Eudragit RS100 and Eudragit RL 100 micropellets.

The objective of the present investigation was to prepare nitrofurantoin micropellets coated with a combination of Eudragit RS 100 and Eudragit RL100 taken in varying ratios to achieve a sustained nitrofurantoin serum and urinary level over a prolonged period of time without any side effect. The method adopted was phase separation coacervation induced by non-solvent addition. The physical nature of the coating film was improved by a protective colloid, polyisobutylene (0% to 3% w/w). The optimized formulations were extensively evaluated for particle size analysis, Scanning Electron Microscopy, stability studies and finally in vitro and in vivo release studies and their statistical evaluation and correlation.

Acrylic Resins↗
PubMed1999

Conditionally adherent growth of serum-independent CHO cells for automated drug screening and biopharmaceutical production.

SSF3 is a CHO cell line adapted for growth in protein-free medium. It grows in suspension unless serum-derived attachment factors such as vitronectin are added to the medium. Serum-independent cell lines, which adhere to the substrate after induction with dexamethasone or constitutively, were created by transfection with a human vitronectin gene under control of the mouse mammary tumor-virus promoter. Substrate attachment and SSF3VN-cell spreading could be prevented with an RGD peptide (arginine-glycine-aspartic acid) confirming that attachment is mediated by an intregrin receptor. Hormone-inducible attachment could be blocked by glucocorticoid antagonist promegestone. All steps in the isolation of stable transfected SSF3VN cell lines could be done in a chemically defined medium avoiding the risk of introduction of serum-derived infectious agents. SSF3VN cells could be grown in protein-free medium in solid-phase large-scale bioreactors. Application in microplates as used in high-throughput screening was demonstrated in an assay of Ca(2+) release from internal stores induced by agonist-binding to recombinant human metabotropic glutamate receptor hmGluR1b.

Animals↗
PubMedDate not supplied

[Comparative biopharmaceutical study of tegalide].

The investigations have indicated a great influence of pharmaceutical factors on the pharmacokinetics of tegalide. The agent as tablets has a higher bioavailability than its substance. The high bioavailability of tegalide tablets appears to be associated with the presence of auxiliaries in them, which enhance the magnitude of the agent's absorption. Differences in the shelf lives of tablets affect their bioavailability. In this connection, the shelf life must be limited in terms of the pharmacological data presented.

Absorption↗
PubMed2001

Chitosan based pentazocine microspheres for intranasal systemic delivery: development and biopharmaceutical evaluation.

Bioadhesive chitosan microspheres (Ms) of pentazocine (Pz) for intranasal systemic delivery were prepared with the aim of avoiding the first pass effect, and thus improving the bioavailability and achieving sustained and controlled blood level profiles, as an alternative therapy to injection and to obtain improved therapeutic efficacy in the treatment of chronic pain such as cancer, trauma and post-operative pain, etc. The formulation variables were drug loading, polymer concentration, stirring rate during crosslinking and oils. The microspheres (Ms) were subjected to evaluation for physical characteristics, such as particle size, incorporation efficiency, swelling ability, in vitro bioadhesion, in vitro drug release characteristics and in vivo performance in rabbits. Application of in vitro data to various kinetic equations indicated matrix diffusion controlled drug delivery from chitosan Ms. Drug loading, polymer concentration and stirring speed influenced the drug release profiles significantly while oils had negligible effect. In vivo studies indicated significantly improved bioavailability of Pz from Ms with sustained and controlled blood level profiles as compared to i.v., oral and nasal administration of drug solution. Good correlation was observed between in vitro and in vivo data.

Adhesiveness↗