Hydrophilic excipients modulate the time lag of time-controlled disintegrating press-coated tablets

Abstract

An oral press-coated tablet was developed by means of direct compression to achieve the time-controlled disintegrating or rupturing function with a distinct predetermined lag time. This press-coated tablet containing sodium diclofenac in the inner core was formulated with an outer shell by different weight ratios of hydrophobic polymer of micronized ethylcellulose (EC) powder and hydrophilic excipients such as spray-dried lactose (SDL) or hydroxypropyl methylcellulose (HPMC). The effect of the formulation of an outer shell comprising both hydrophobic polymer and hydrophilic excipients on the time lag of drug release was investigated. The release profile of the press-coated tablet exhibited a time period without drug release (time lag) followed by a rapid and complete release phase, in which the outer shell ruptured or broke into 2 halves. The lag phase was markedly dependent on the weight ratios of EC/SDL or EC/HPMC in the outer shell. Different time lags of the press-coated tablets from 1.0 to 16.3 hours could be modulated by changing the type and amount of the excipients. A semilogarithmic plot of the time lag of the tablet against the weight ratios of EC/SDL or EC/HPMC in the outer shell demonstrated a good linear relationship, with r = 0.976 and r = 0.982, respectively. The predetermined time lag prior to the drug release from a presscoated tablet prepared by using a micronized EC as a retarding coating shell can be adequately scheduled with the addition of hydrophilic excipients according to the time or site requirements.

Oral pulsatile delivery: Rationale and chronopharmaceutical formulations

“…Indeed, larger particle dimensions were associated with a higher porosity thus resulting in enhanced shell permeability. As expected, the incorporation of swellable (HPMC, sodium starch glycolate, sodium alginate, glycine max husk) and osmotic (sodium chloride) excipients into the core formulation or of hydrophilic compounds (HPMC, spray-dried lactose) into the outer shell was reflected in shorter delay phases (Lin et al, , 2004aRane et al, 2009). Modifications of half of the coating formula were demonstrated to be a further means of modulating the lag phase.…”

Development and Evaluation of Indomethacin Controlled Release Press Coated Tablets

“…It is preferred by the formulators to modulate drug release mainly due to its claim to form strong viscous gel in contact with water. 16 Formulation IX-HPMC was designed to evaluate the effect of HPMC on drug release from central core matrix tablet. Figure 3 shows the release profile of indomethacin from HPMC loaded press coated tablets.…”

On the Effects of UV Radiation on the Release Ability of Glucose Embedded in Hydroxypropyl Cellulose Films

“…[5] A literature survey on this subject revealed that the type of excipient and the amount used influenced the controlled drug release profile from tablets and this affected the drug bioavailability. [6] Besides biocompatibility, solubility is one of the important factors that has to be considered when designing a controlled release system. Considering the advantages derived from their molecular structure, water-soluble cellulose ethers are currently the most commonly used matrix polymers.…”