Pharmaceutical dosage forms contain both pharmacologically active compounds and excipients added to aid the formulation and manufacture of the subsequent dosage form for administration to patients. Indeed, the properties of the final dosage form (i.e. its bioavailability and stability) are, for the most part, highly dependent on the excipients chosen, their concentration and interaction with both the active compound and each other. No longer can excipients be regarded simply as inert or inactive ingredients, and a detailed knowledge not only of the physical and chemical properties but also of the safety, handling and regulatory status of these materials is essential for formulators throughout the world. In addition, the growth of novel forms of delivery has resulted in an increase in the number of the excipients being used and suppliers of excipients have developed novel coprocessed excipient mixtures and new physical forms to improve their properties. The Handbook of Pharmaceutical Excipients has been conceived as a systematic, comprehensive resource of information ​ on all of these topics. URI http://repositorio.ub.edu.ar/handle/123456789/5143 Collections Libros Farmacia www.ub.edu.ar | biblioteca.ub.edu.ar Contact Us | Send Feedback Handbook of pharmaceutical excipients 

Handbook of Pharmaceutical Excipients

Novel mechanisms and devices to enable successful transdermal drug delivery.

Poloxamer 407 copolymer (ethylene oxide and propylene oxide blocks) shows thermoreversible properties, which is of the utmost interest in optimising drug formulation (fluid state at room temperature facilitating administration and gel state above sol-gel transition temperature at body temperature promoting prolonged release of pharmacological agents). Pharmaceutical evaluation consists in determining the rheological behaviour (flow curve or oscillatory studies), sol-gel transition temperature, in vitro drug release using either synthetic or physiological membrane and (bio)adhesion characteristics. Poloxamer 407 formulations led to enhanced solubilisation of poorly water-soluble drugs and prolonged release profile for many galenic applications (e.g., oral, rectal, topical, ophthalmic, nasal and injectable preparations) but did not clearly show any relevant advantages when used alone. Combination with other excipients like Poloxamer 188 or mucoadhesive polymers promotes Poloxamer 407 action by optimising sol-gel transition temperature or increasing bioadhesive properties. Inclusion of liposomes or micro(nano)particles in Poloxamer 407 formulations offers interesting prospects, as well. Besides these promising data, Poloxamer 407 has been held responsible for lipidic profile alteration and possible renal toxicity, which compromises its development for parenteral applications. In addition, new findings have demonstrated immuno-modulation and cytotoxicity-promoting properties of Poloxamer 407 revealing significant pharmacological interest and, hence, human trials are in progress to specify these potential applications.

A Review of Poloxamer 407 Pharmaceutical and Pharmacological Characteristics

The Merck Index of Chemicals and Drugs An Encyclopedia for the Chemist, Pharmacist, Physician and Allied Professions Sixth edition Pp xiv + 1167 (Rahway, NJ: Merck and Company, Inc, 1952) 750 dollars; thumb-indexed, 8 dollars

The Merck Index

Poly(ethylene oxide)–poly(propylene oxide) block copolymer micelles as drug delivery agents: Improved hydrosolubility, stability and bioavailability of drugs

Controlled-release matrix tablets of ibuprofen using cellulose ethers and carrageenans: effect of formulation factors on dissolution rates.

Physicochemical and release studies of naproxen in poloxamer gels

Physicochemical studies of lidocaine-menthol binary systems for enhanced membrane transport.

The pharmacokinetic profiles of naproxen in blood and synovial fluid (SF) following topical and i.v. bolus administration in dogs, and the local tissue disposition of the drug following topical and oral administration in rats, were investigated to assess the feasibility of topical delivery of naproxen for local and systemic effects. The naproxen gel in poloxamer 407 (PF-127) was applied on the stifle joint of dogs, and serum and synovial fluid samples were collected. For local tissue disposition studies, the naproxen gel was applied on the dorsal skin in rats, and blood, skin, and muscle samples were taken at 3, 6, and 12 h postdose after removing the residual gel from the skin. Steady state serum concentrations occurred at approximately 20 h after topical doses and lasted for the next approximately 30 h in dogs. Similar SF-serum concentration ratios of naproxen were found between i.v. (0.61 +/- 0.16) and topical (0.55 +/- 0.14) routes of administration. Following the i.v. dose, the half-life of naproxen in SF (approximately 60 h) was significantly longer than that in serum (approximately 40 h). The bioavailability of naproxen in the topical gel was approximately 2% of the applied dose in dogs. A large accumulation of drug in the epidermis, dermis, and muscle tissue beneath the gel application site was found in rats. Isopropyl myristate (IPM) significantly increased the systemic absorption as well as the concentrations of naproxen in the underlying dermis and muscle tissues, but exerted little effect on the disposition of naproxen in the epidermis.

H. W. Jun

Papers

Controlled-release matrix tablets of ibuprofen using cellulose ethers and carrageenans: effect of formulation factors on dissolution rates.

Physicochemical and release studies of naproxen in poloxamer gels

Physicochemical studies of lidocaine-menthol binary systems for enhanced membrane transport.

Pharmacokinetic and local tissue disposition studies of naproxen-following topical and systemic administration in dogs and rats.

HPLC assay of Lidocaine in plasma with solid phase extraction and UV detection.