Development Of Controlled Release Tablet Formulation Using Hydrophilic Polymer Matrix Systems
To develop large diameter, non-disintegrating controlled release tablet formulations using hydrophilic polymer matrix systems for pH sensitive low solubility drugs.
Formulations containing a pH solubility sensitive drug and a combination of hydrophilic polymers (HPMC and Polyox) and alkalizers (such as calcium carbonate, magnesium oxide and sodium bicarbonate) were designed and manufactured using direct compression or roller compaction followed by compression using rotary tablet press. The investigation was aimed to provide an alkaline micro-environment to a chernical entity which has a very poor solubility up to pH of 6.8. The tablets were subjected to prolonged exposure to various pH environments (pH range 1.0 to 7.4) and studied for effect of various pHs on in- vitro release profile using USP dissolution apparatus Ill method. Selected formulations were tested for physical appearance, dissolution, content and impurities after storage at 40°C/75%RH for up to 6 months.
Large, non-disintegrating controlled release tablet formulations using hydrophilic polymer matrix systems were designed and developed to release the drug for 7-9 hours (Formula. 1 A/2A) and 10-12 hours (Formula 2A/2B) respectively with zero to pseudo zero order release profiles. No significant changes in physical appearance, stability and dissolution were observed from the stability samples. The data showed significant influence of the alkalizers on the dissolution profile of the tablets. The molecular weights and type of hydrophilic polymers also influence the tablet strength and drug release mechanism (i.e. erosion or diffusion) from the matrix tablets during in-vitro dissolution. With suitable combination of excipients, floating tablets in dissolution fluids were produced.