Carbopol 940 CAS 76050-42-5

When Carbopol 940 is an anionic adhesive, it cannot be used in combination with divalent basic drugs to avoid precipitation. The bioadhesive drug delivery system (BDDS) acts on the epidermal cell mucosa or skin surface of various cavities, such as the gastrointestinal tract, vagina, oral cavity, nasal cavity, epidermis, etc. The dosage forms include tablets, films, gels doses, sticks, etc. Among them, gel is a new type of bioadhesive drug delivery system that has developed rapidly in recent years. It has good dispersibility, strong adhesion, good stability, long-lasting efficacy, convenient application, and can avoid first-pass effect and administration site. Advantages of high concentration.

1) Gastrointestinal bioadhesives

The sulpiride matrix sustained-release retention tablet made of Carbopol 940 can adhere to the surface of gastrointestinal mucin or epithelial cells to prolong the retention time and achieve the purpose of sustained release. In vivo studies in rabbits show that compared with oral solution and powder injection, the AUC of the sustained-release retention tablet can be increased by more than 1 times, the mean retention time (MRT) can be prolonged by 4 to 5 times, and the bioavailability is improved.

2) Vaginal bioadhesives

Gel of metronidazole liposomes and clotrimazole liposomes with carbomer 974NF in the treatment of vaginitis. The in vitro test showed that about 50% metronidazole and 30% clotrimazole remained in the gels after the two drug-containing liposome gels were released for 24 hours. And the stability test showed that carbomer 974NF could maintain two kinds of liposome particle size distribution, indicating that the bioadhesive liposome gel is suitable for local treatment of vaginal diseases. In order to avoid the removal of the uterus in patients with uterine cancer, the preparation based on Carbopol 940 can be administered through the vagina to make the drug adhere to the uterine mucosa, kill cancer cells without damaging normal cells, and avoid removal of the uterus.

Using an appropriate proportion of hydroxypropyl cellulose (HPC) and carbomer as an adhesive, bleomycin can be directly compressed into a tablet or made into a duckbill suppository, which can be adhered to the cervix, and the formulation can be seen after 24 hours. Therefore, it is speculated that the dosage form can achieve satisfactory results in the treatment of uterine cancer.

3) Oral bioadhesive

After the drug is absorbed through the oral mucosa, it can directly enter the systemic circulation to avoid the first-pass effect. The apparent release rate constant of felodipine oral mucoadhesive tablets prepared with hypromellose (HPMC) K4M and carbomer 974P as bioadhesive polymers was 3.3% h-1, and the average adhesive force was 131.08-181.35g. It has been verified by in vivo experiments that the preparation has suitable adhesion to the oral cavity and is less irritating to the oral mucosa. In order to obtain a good effect on the treatment of periodontitis, metronidazole oral adhesive tablets were prepared with carbomer 940 and hydroxyethyl cellulose (HEC). It can be slowly released in the oral cavity, and the drug concentration detected in 12h is higher than the minimum inhibitory concentration.

4) Nasal bioadhesives

Nasal administration can be used for special patients where oral and intravenous administration is inconvenient or difficult to implement. Using Carbomer 971P as an excipient, apomorphine nasal powder was developed. The research on its sustained release shows that the bioavailability of this dosage form is equivalent to that of subcutaneous injection, and it has a sustained release effect. Najafabadi et al [14] reported that insulin was made into a carbomer gel spray.

1) Solid preparation

The tablet made of Carbopol 940 as the hydrophilic gel skeleton gradually absorbs water and swells in the release medium, and the drug gradually diffuses to the surface of the tablet for release. As the gel content increases, the swelling layer thickens and the drug release rate gradually slows down.

2) Injection

In recent years, the development of sustained-release injection drug delivery systems has attracted the attention of many pharmaceutical researchers. The drug delivery system can be implanted at a fixed point, release the drug locally, and release the drug for a long time. It can reduce the adverse drug reaction and improve the compliance of patients. The cyclosporine liposomes modified with carbomer 941 were administered intravenously to rats, the results showed that the transport of cyclosporine to the spleen and liver and other organs was significantly increased, and the concentration ratio of cyclosporine in tissue/plasma was the same as that of ordinary liposomes 2 times.

In the heart transplantation test, the average survival time of the rats in the Carbopol 940-modified liposome group, the ordinary liposome group and the control solution group was 18.8, 14.2 and 7.6 days, respectively. According to Fick’s first law of diffusion, the viscosity of liposomes modified by Carbopol 940 increases, the diffusion rate of the drug is slowed down, and the residence time of the drug in the body is prolonged, thereby enhancing the targeted transport and immunosuppressive effects of the drug.

1) Gel for skin

The gel is used on the skin surface, with good spreadability, no greasy feeling, and no pollution to clothes. The transdermal absorption rate is faster than that of the cream. Compared with the external solution, the gel has a longer residence time on the skin surface. The clemastine fumarate gel prepared with 1% carbomer 940 has good uniformity and dispersibility, simple preparation process and controllable quality.

2) Eye gel

Many ophthalmic drugs are poorly absorbed, mainly due to the accelerated elimination of tears. The ophthalmic gel prepared with carbomer can prolong the residence time of the drug in the eye and increase the absorption of the drug.

3) Gel for teeth

The triclosan dental paste prepared with carbomer 974P showed a zero-order release pattern. There are other reports,

The use of carbomer gel matrix has good adhesion and film-forming properties, and the addition of protein coagulants containing desensitizing drugs formaldehyde and thymol can prolong the time that the drug stays locally on the teeth and enhance the desensitization effect.

The main function of carbomer for oral suspension is to thicken, improve system rheology, suspend and provide bioadhesion. Carbomer can form a uniformly dispersed skeleton system in water, and insoluble components can be wrapped in the skeleton gap of the system. The physical stability and stabilization mechanism of the resin microcapsule suspension were studied, and it was shown that the carbomer exerted a stabilizing effect through single-point or multi-point adsorption with the resin microcapsule to generate space bridges.

Using Carbomer 934 as the suspending agent to prepare the aluminum hydroxide suspension, after shaking and sub-packaging, the particles settle slowly, do not agglomerate after settling, and have good dispersibility, which overcomes the tendency of the gel to become sticky and agglomerated during storage, and it is not easy to dumping phenomenon. The clarithromycin dry suspension prepared with 0.3%-0.5% carbomer 974P NF as the suspending agent, the whole system is relatively uniform and stable, and the sedimentation ratio conforms to the provisions of the 2000 edition of the Chinese Pharmacopoeia.