Bioadhesives polycarbophil

In vivo methods, which are few, measure the residence time of bioadhesives at the application site [47]. Techniques like y-scintigraphy, the perfused intestinal loop and radiolabeled transit studies using Cr-labeled bioadhesive polymer [48] and Tc-labeled polycarbophil [49] have been employed for this purpose. 

A novel concept of using bioadhesive polymers as enzyme inhibitors has been developed [97]. Included are derivatives of poly acrylic acid, polycarbophil, and car-bomer to protect therapeutically important proteins and peptides from proteolytic activity of enzymes, endopeptidases (trypsin and a-chymotrypsin), exopeptidases (carboxypeptidases A and B), and microsomal and cytosolic leucine aminopeptidase. However, cysteine protease (pyroglutamyl aminopeptidase) is not inhibited by polycarbophil and carbomer [97]. 

Miphil (Columbia Laboratories Inc., Livingston, NJ, USA), a marketed bioadhesive gel based on polycarbophil and capable of reducing vaginal pH, has been used in combination with oral tinidazol for the treatment of bacterial vaginosis. In a multicenter, randomized, investigator-blinded, controlled clinical trial, the combination of the antibiotic with the... 

Polycarbophil-based bioadhesive tablets of metronidazole were tested for adhesion on bovine submaxillary mucin [74]. In a more recent study, metronidazole tablets based on a mixture of modified starch-polyacrylic acid showed an increased potential for the treatment of bacterial vaginosis [75]. 

Bernkop-Schnurch A, Marschtitz MK (1997) Development and in vivo evaluation of systems to protect peptide drugs from aminopeptidase N. Pharm Res 14 181-185 Bernkop-Schnurch A, Paikl C, Valenta C (1997) Novel bioadhesive chitosan-EDTA conjugate protects leucine enkephalin from degradation by aminopeptidase N. Pharm Res 14 917-922 Bernkop-Schnurch A, Thaler S (2000) Polycarbophil-cysteine conjugates as platforms for oral (poly)peptide delivery systems. J Pharm Sci 89 901-909 Bernkop-Schnurch A, Walker G, Zarti H (2001) Thiolation of polycarbophil enhances its inhibition of intestinal brush border membrane bound aminopeptidase N. J Pharm Sci 90 1907-1914... 

Research on nasal powder drug delivery has employed polymers such as starch, dextrans, polyacrylic acid derivatives (e.g., carbopol, polycarbophil), cellulose derivatives (microcrystalline cellulose, semicrystalline cellulose, hydroxypropylmethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose), chitosan, sodium alginate, hyaluronans, and polyanhydrides such as poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA). Many of these polymers have already been used as excipients in pharmaceutical formulations and are often referred to as first-generation bioadhesives [38-45], In nasal dry powder a single bioadhesive polymer or a... 

Polycarbophil, poly(acrylic acid) polymers crosslinked with divinyl glycol, is available for bioadhesive or medicinal applications. Carbomers designated with the letter P , e.g. carbomer 971P, are the only pharmaceutical grades of polymer accepted for oral or mucosal contact products. These resins are particularly useful in the production of clear gels. 

Calcium/sodium PVM/MA copolymer N-Methyl-2-pyrrolidone PVM/MA copolymer bioadhesive, pharmaceuticals Polycarbophil... 

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