Carbomer, also known as Carbopol, is a high-molecular polymer cross-linked with acrylic acid and allyl sucrose ether or allyl pentaerythritol ether. Carbomer’s research began in the 1950s and was first developed and produced by Goodrich in the United States. By the 1970s and 1980s, the research on carbomer became mature and has been widely used, mainly in cosmetics and Pharmaceutical research and production. The following Desheng mainly explains the application of carbomer in bioadhesive drug delivery system.
When carbomer is an anionic adhesive, it should not be used in combination with divalent basic drugs to avoid precipitation. The bioadhesive drug delivery system (BDDS) acts on various cavity epidermal cell mucosa or skin surface, such as gastrointestinal tract, vagina, oral cavity, nasal cavity, epidermis, etc. The dosage forms are tablets, membranes, and gels. Agent, stick, etc. Among them, gel is a new type of bioadhesive drug release system that has developed rapidly in recent years. It has good dispersion, strong adhesion, good stability, long-lasting drug effect, convenient application, and can avoid the first pass effect and the site of administration. Advantages of high concentration.
(1) Gastrointestinal bioadhesive
Sulpiride skeleton sustained-release retention tablets made of carbomer can adhere to the surface of gastrointestinal mucin or epithelial cells, prolong the retention time and achieve the purpose of sustained release. In vivo studies in rabbits have shown that compared with oral solutions and powder injections, the AUC of the sustained-release retention tablet can be increased by more than 1 time, the mean retention time (MRT) can be extended by 4 to 5 times, and the bioavailability is improved.
(2) Vaginal bioadhesive
Carbomer 974NF was used to make metronidazole liposome and clotrimazole liposome into gel to treat vaginitis. In vitro experiments showed that after 24 hours of release of the two drug-containing liposome gels, approximately 50% metronidazole and 30% clotrimazole remained in the gels. And the stability test shows that Carbomer 974NF can maintain the particle size distribution of two liposomes, indicating that the bioadhesive liposome gel is suitable for local treatment of vaginal diseases. In order to avoid removal of the uterus in patients with uterine cancer, carbomer-based preparations can be administered through the vagina to allow the drug to adhere to the uterine mucosa, kill cancer cells without damaging normal cells, and avoid removing the uterus.
Using an appropriate ratio of hydroxypropyl cellulose (HPC) and carbomer as an adhesive, the bleomycin can be directly pressed into tablets or made into a duckbill suppository, which can be adhered to the cervix, and the preparation remains in its original shape after being taken out after 24 hours. It is speculated that this dosage form can achieve satisfactory results when used in the treatment of uterine cancer.
(3) Oral bioadhesive
The drug can directly enter the systemic circulation after being absorbed by the oral mucosa, avoiding the first pass effect. The felodipine oral mucosal adhesive sheet prepared with hypromellose (HPMC) K4M and carbomer 974P as bioadhesive polymers has an apparent release rate constant of 3.3% h-1, and an average adhesive force of 131.08～181.35g. It has been verified by in vivo experiments that the preparation has a suitable adhesion force to the oral cavity and is less irritating to the oral mucosa. In order to obtain a good treatment of periodontitis, metronidazole oral adhesive tablets were prepared with carbomer 940 and hydroxyethyl cellulose (HEC). When the ratio of the two is 1:1, the drug loading of the product is 20mg. It can be released slowly in the oral cavity, and the drug concentration detected at 12h is higher than the minimum inhibitory concentration.
(4) Bioadhesive for nose
Nasal administration can be aimed at special patients who are inconvenient or difficult to implement oral and intravenous administration. Carbomer 971P was used as an auxiliary material to develop apomorphine nasal powder mist. The sustained release study showed that the bioavailability of this dosage form is equivalent to that of subcutaneous injection, and it has sustained release effect. Najafabadi et al. reported that insulin was made into card Pom gel spray.
Carbomer can be divided into products of various specifications according to the degree of polymerization. The application of products of each specification will vary due to the degree of polymerization and viscosity. Among them, carbomer 934, 940, 941, etc. are the most widely used. . Desheng is one of the manufacturers of Carbomer, which can provide Carbomer 940 and 980, and you can call for consultation if you need it.
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