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The advantages of using superdisintegrants, sodium starch glycolate (SSG), croscarmellose sodium (CCS) and crospovidone (CP) over traditional high molecular weight (MW) viscosity enhancing agents, guar gum (GG), xanthan gum (XG), pectin and high MW HPMC are examined for improving drug content uniformity without compromising dissolution of films containing nanoparticles of griseofulvin (GF), used as a model poorly water-soluble drug. Films were fabricated by preparing low MW HPMC solutions to which a fixed amount of viscosity enhancing agents were added and mixed with GF nanosuspensions produced via wet milling, followed by casting and drying. The addition of superdisintegrants and high MW HPMC, led to an increase in viscosity of precursor suspensions without GF particle aggregation, and hence excellent drug content uniformity along with retention of the high surface area of the GF nanoparticles in dried films. In contrast, addition of XG and pectin resulted in aggregation of GF particles in suspensions, leading to poor content uniformity and incomplete recovery of GF nanoparticles upon redispersion of dried films. In spite of their high precursor viscosity, the films containing superdisintegrants did not lead to increased mechanical strength and demonstrated fast drug release, suggesting faster matrix erosion. In contrast, films with high MW polymers (GG, XG, and pectin and high MW HPMC) had increased mechanical strength and their subsequent slow erosion/disintegration along with longer hydration times resulted in significant delay of drug release, which was found to be directly proportional to their MW. These results demonstrate novel use for superdisintegrants as economical and superior alternative to traditional viscosity enhancing agents in forming drug laden biocompatible polymer films.

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A closed form solution has been obtained for the release kinetics of a solute from a spherical drug matrix into a finite volume of liquid, taking into account the effect of rate of absorption. The proposed model results clearly show the effect of the absorption rate constant on the rate of drug release. The obtained results are compared with the experimental data and diffusion-only model results. There is a significant difference in the release profile when the rate of absorption of drug is slow. The most important feature of the mathematical relationship between the liquid concentration verses time is its ability to predict change in the performance of the drug by manipulating the parameters of the equation. These parameters include the initial concentration of the drug, the radius of the drug and diffusivity of the drug in the solid to name a few. Therefore, a substantial number of experiments can be eliminated when the optimal performance of a drug is sought after.