Poly Carbopol

Polycarbophil-cysteine [67,68], Carbopol(974 P)-cysteine [69], poly(acrylic acid)-bacitracin conjugate [52], chitosan-EDTA conjugate [52,64], chitosan-EDTA-antipain, chymostatin, and elastatinal conjugate [171]... 

Ion exchange resins (methacrylic acid, sulfonated polystyrene/divinylbenzene) Polyacrylic acid (Carbopol) Poly(MMA/MAA)... 

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... 

A review of vaginal bioadhesive formulations indicates that bioadhesive tablets have been used for localized treatment of diseases in the vaginal tissue.F ° l For example. Bleomycin, an antitumor agent, was incorporated into a flat-faced disk fabricated from a combination of hydroxypropyl cellulose and poly-(acrylic acid) (Carbopol 934). ° The tablet was designed to release Bleomycin at a slow rate to minimize irritation to healthy mucosa. Another vaginal tablet is formulated from the combination of poly(acrylic acid) with hydroxypropyl methylcellulose and ethylcellu-lose. Other polymer combinations evaluated for potential bioadhesive vaginal delivery include poly(acrylic acid) and sodium carboxymethyl cellulose with Avicel PH102 (methylcellulose) as the diluent. Insulin has been formulated in a cross-linked poly(acrylic acid) gel... 

Carbomers are synthetic, high-molecular-weight, crosslinked polymers of acrylic acid. These poly(acrylic acid) polymers are crosslinked with allyl sucrose or allyl pentaerythritol. The polymerization solvent used most commonly was benzene however, some of the newer commercially available grades of carbomer are manufactured using either ethyl acetate or a cyclohexane-ethyl acetate cosolvent mixture. The Carbopol ETD resins are produced in the cosolvent mixture with a proprietary polymerization aid, and these resins are crosslinked with a polyalkenyl polyether. 

Tablets for vaginal use have included hydroxypropylcellulose or sodium carboxy-methylcellulose and poly(acrylic acid) (such as Carbopol 934) as excipients. Micropatches in the size range fO-fOO,am in diameter prepared from starch, gelatin, albumin, collagen...

FIG. 11 Pseudophase diagram for 30 wt% cyclohexane in water stabilized by PAA (Carbopol 980). The c values are shown as the curve drawn in the bottom left-hand corner of the diagram. (Reprinted from Colloids and Surfaces A Physicochem Eng Aspects, 88, Lockhead RY, Rulinson CJ, An investigation of the mechanism by which hydrophobically modified hydrophilic polymers act as primary emulsifiers for oil in water emulsions. 1. Poly(acrylic acids) and hydroxyethyl celluloses. 27-32, Copyright (1994), with permission from Elsevier Science.)... 

Drugs like spantide II and ketoprofen, which are effective against allergic contact dermatitis and psoriatic plaque, can be transformed into nanogels by using hydroxypropyl methylcellulose (HPMC) and carbopol with the desired viscosity. BUayered nanoparticles from poly-(lactide-co-glycohc acid) and chitosan were prepared using surface modification with oleic acid. 

The following commercially available polymer samples were used as received poly(vinyl alcohol), PVA (Polyviol, Wacker Chemie GmbH) hydroxypropylcellulose, HPC (Klucel, Hercules Inc.) poly(acrylic acid), PAA (Carbopol 940, Goodrich Chemical Co.). Some properties of the polymers are reported in Table 1. 

Lin S-Y, Yu H-L (1999) Thermal stabdity of methacrylic acid copolymers of Eudragits L, S, and L30D and the acrylic acid polymer of carbopol. J Poly m Sci Part A Polym Chem 37 2061-2067... 

Poly(acrylic acid) (PAA) (Figure 16.5) is an anionic mucoadhesive polymer produced by the radical polymerization of acrylic add. PAA and its derivatives—weakly crosslinked PAAs, also known as Carbomers or Carbopol—are widely used in ophthalmic formulation, such as the ones used for the management of the dry eye condition. Generally, PAA and its derivatives are used in the preparation of mucoadhesive ocular drug delivery formulations [25], either in the form of viscous gels [26], nanoparticles... 

The most commonly used cross-linked polymer gels are those based on poly(acrylic add) (Carbopol, Goodric). On neutralisation with alkali (such as KOH or ethanolamine), ionisation of the COOH groups occurs, resulting in swelling (by double layer expansion), and a gel can be produced at low concentrations. 

Kanis, L.A., Viel, F.C., Crespo, J.S., Bertolino, J.R., Pires, A.T.N., and Soldi, V. (2000) Study of poly (ethylene oxide)/ carbopol blends through thermal analysis and infrared spectroscopy. Polymer, 41, 3303-3309. 

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