Pharmaceutical significance of cellulose: A review

Abstract

Abstract. The amalgamation of polymer and pharmaceutical sciences led to the introduction of polymer in the design and development of drug delivery systems. Polymeric delivery systems are mainly intended to achieve controlled or sustained drug delivery. Polysaccharides fabricated into hydrophilic matrices remain popular biomaterials for controlled-release dosage forms and the most abundant naturally occurring biopolymer is cellulose; so hdroxypropylmethyl cellulose, hydroxypropyl cellulose, microcrystalline cellulose and hydroxyethyl cellulose can be used for production of time controlled delivery systems. Additionally microcrystalline cellulose, sodium carboxymethyl cellulose, hydroxypropylmethyl cellulose, hydroxyethyl cellulose as well as hydroxypropyl cellulose are used to coat tablets. Cellulose acetate phthalate and hydroxymethyl cellulose phthalate are also used for enteric coating of tablets. Targeting of drugs to the colon following oral administration has also been accomplished by using polysaccharides such as hdroxypropylmethyl cellulose and hydroxypropyl cellulose in hydrated form; also they act as binders that swell when hydrated by gastric media and delay absorption. This paper assembles the current knowledge on the structure and chemistry of cellulose, and in the development of innovative cellulose esters and ethers for pharmaceuticals.

Evaluation of hard gelatin capsules and hydroxypropyl methylcellulose containing ampicillin

“…This fact can be explained because HPMC is a forming polymer of hydrophilic matrix used to promote a slower release of the drug conditioned in the capsules. [20][21][22][23] The value found for the reference medicine (90.47%) resemble the values obtained for the capsules elaborated with HPMC, although this product is made from hard gelatin capsule. This may be related to the present excipients in the reference medicine (lactose, methylcellulose, stearic acid and magnesium stearate), which are different from the excipients used in the B formulation.…”

“…The choice of hydrophilic polymer in the matrix formulation can provide an appropriate combination of the swelling mechanisms, dissolution or erosion and determine the release kinetics in vitro. 21 According to previous work, 22 the drug incorporation in hydrophilic matrix systems is the most used method to prolong drug release dosage forms for oral use. It was observed that with increasing amounts of HPMC in the formulations it is possible to get a reduced release of the drug, which can be evidenced in the dissolution tests.…”

“…This fact can be explained once the hydrophilic matrix, when in contact with the dissolution medium, swell and form a gelled layer that controls the subsequent entrance of water into the matrix and drug release, prolonging its release. [21][22][23] The speed of water penetration in the matrix system determines the mode of drug release. In high concentrations, the linear chains of HPMC form a tangle and result in a gelatinous layer, fairly consistent, hindering the release of the active principle.…”

“…At very low concentrations, these cellulose gels have very low viscosity, allowing almost immediate release of drugs. 21 The average values of ED% are shown in Table 3 and the graphical representation is shown in Figure 2.…”

Preparation, properties, and antibacterial behavior of a novel cellulose derivative containing lactam groups

“…4 The main drawback to the use of cellulose for industrial applications is its insolubility in organic and aqueous solvents, with the supramolecular structures within and between polysaccharide strands being primarily responsible for insolubility. 3,[5][6][7] Chemical modification of the hydroxyl groups at C2, C3, and/ or C6 positions of cellulose has been developed to confer novel properties, including hydrophilic, antimicrobial, and thermoplastic character, where the degree of substitution (DS) and distribution of the substituents determines the modified cellulose structure and behavior. For cellulosebased materials, DS represents the average number of modified hydroxyl groups per AGU unit, where DS values can range from 0 to 3.…”