Double-Layered Matrix of Shellac Wax-Lutrol in Controlled Dual Drug Release

Abstract

Abstract. Double-layered matrix tablets prepared from shellac wax-lutrol were fabricated using a molding technique, and the release of hydrochlorothiazide and propranolol HCl from the inner tablet or outer layer was studied. The simultaneous determination of dual drug release was measured with first derivative UV spectrophotometry. The tablet containing shellac wax as the outer tablet and lutrol as the inner tablet showed more appropriate drug release and the size of the inner layer influenced the rate of drug release. In addition, the aqueous solubility of the drug and the components of the inner tablet or outer layer affected the drug release behavior. Most of the double-layered tablets exhibited the drug-release pattern which fitted well with zero-order kinetic due to the restriction of the release surface. Biphasic drug release pattern was found in the tablet of which the outer layer rapidly eroded. The drug dissolution data from drug-loaded-outer layer could predict the dissolution time for the outer layer of drug-loaded inner part of double-layered matrix tablet. Incorporation of lutrol increased the drug release from shellac wax matrix, and the zero-order release was attained by fabricating it into a double-layered tablet.

Multiscale Shellac-Based Delivery Systems: From Macro- to Nanoscale

“…The release of hydrophilic propranolol hydrochloride in a dual drug formulation (propranolol hydrochloride and hydrochlorothiazide) with a 7:3 ratio of lutrol to shellac was slower than that of the individual drug formulation, which can be attributed to the addition of the hydrophobic hydrochlorothiazide that increased the strength of the gel in the tablet . Further research suggested that the components and the surface area affect the drug release behavior of double-layered matrix tablets . As shown in Figure B, double-layer matrix tablets with an erodible inner drug-loaded layer and an erodible outer layer exhibited biphasic drug release.…”

“…However, the drug release of matrix tablets with an insoluble outer layer and an erodible inner drug-loaded layer followed zero-order kinetics owing to the unexposed inner surface area. Outer drug-loaded matrix tablets performed faster drug release than the inner drug-loaded matrix tablets and did not exhibit biphasic drug release …”

“…Drug release from shellac-based matrix tablets is influenced by various factors, such as reaction conditions, ,,− additive − and drug patterns, , and matrix forms, as shown in Table . Shellac-based tablets with controlled drug release behaviors can be prepared by annealing. , Increasing the annealing temperature and shellac content improves the hardness and disintegration time of shellac-based tablets and converts the drug release kinetics from relaxation-controlled to diffusion-controlled release through the in situ polymerization of shellac during annealing. , Similar to the increase in hardness caused by annealing, matrix tablets annealed at 100 °C showed significantly less erosion after a dissolution test (Figure A), which might contribute to a slower drug release .…”

“…Thus, the hydrophilicity of the matrix tablets should be adjusted to achieve the desired drug release effect. The modification of shellac-based matrix tablets by incorporating hydrophilic polymers could tune up the drug release rate, thereby solving this problem. , Lutrol was incorporated into the shellac tablets prepared by fusion and molding techniques to regulate the drug release. A lower hydrophilic lutrol content promoted the erosion of the shellac matrix tablets by enhancing water absorption, thereby facilitating drug release.…”

“…A lower hydrophilic lutrol content promoted the erosion of the shellac matrix tablets by enhancing water absorption, thereby facilitating drug release. In contrast, a high lutrol content led to the formation of a gel in water, resulting in the swelling of the tablet and prolonging drug release. , The release of multidrug components from a tablet is influenced by the physicochemical properties of the individual drug components. The release of hydrophilic propranolol hydrochloride in a dual drug formulation (propranolol hydrochloride and hydrochlorothiazide) with a 7:3 ratio of lutrol to shellac was slower than that of the individual drug formulation, which can be attributed to the addition of the hydrophobic hydrochlorothiazide that increased the strength of the gel in the tablet .…”