Nystatin is commonly employed to treat fungal infections in the mouth. It is not absorbed via the stomach and it will therefore not treat fungal infections in any part of the body other than the mouth. Nystatin buccoadhesive tablets release the drug very slowly due to the poor solubility of nystatin in water and also the presence of polymers with mucoadhesive properties. Therefore, the aim of the present study was to improve drug release from buccoadhesive tablets, while retaining adequate mucoadhesive properties. To this end, a solid dispersion of nystatin: lactose (1:3) was prepared and mixed with xanthan. The effects of hydrophilic surfactants such as cremophor RH40 and Tween 80 on drug release and mucoadhesive properties of nystatin tablets were also investigated as were swelling and erosion indices and strength of bioadhesion in vitro to a biological membrane. The interaction between nystatin and lactose in solid dispersion formulation was investigated by XRPD, FT-IR and DSC. The results showed that a solid dispersion formulation and mucoadhesive tablets containing surfactants led to faster drug release than their simple physical mixtures. Drug release was also faster from a solid dispersion compared to tablets containing surfactants. Swelling and erosion results showed that tablets made of a solid dispersion swelled and eroded faster than a physical mixture formulation. The presence of surfactant slightly increased the degree of swelling and erosion of buccoadhesive tablets.

The prepared waxy matrix tablet containing NC complexes with CD shows promising results as extended release tablets.

The effect of packaging and storage on carbamazepine (CBZ) tablets was examined using Tegretol and Tegral, dispensed in strip seals, and Finlepsin, dispensed in bottles. Tegretol and Tegral tablets were stored in their original strips at 40 degrees C, 50 degrees C, and 60 degrees C for 6 months, 3 months, and 1 month, respectively, at 75% relative humidity (RH). Also, tablets were removed from their strips, placed in bottles, and exposed daily to 97% RH at 40 degrees C for 5 min for 30 days. Finlepsin tablets were exposed to 97% RH at 25 degrees C or 40 degrees C for 1 month by removing bottle caps daily for 5 min. Dissolution was used to assess in vitro tablet performance, and high-performance liquid chromatography (HPLC) was used to evaluate the chemical stability of CBZ. Results show that Tegretol tablets were not affected by the tested stress conditions. Tegral tablets, stored in their strips at 50 degrees C or 60 degrees C and 75% RH, showed increased disintegration and dissolution. The effect of 40 degrees C/75% RH for 6 months was similar to 1-month storage at 40 degrees C/97% RH; the tablets hardened and dissolved less than fresh Tegral tablets. Removal of Tegral tablets from their original strips resulted in only 7% dissolved in 60 min. For Finlepsin, the effect of 97% RH at 40 degrees C was more profound than 97% RH at 25 degrees C, but both conditions caused a decrease in dissolution, the extent of which was dependent on tablet position in the bottle. Stressed CBZ tablets, however, showed no change in the chemical stability of CBZ under all tested conditions.

Various buccoadhesive nystatin tablets formulations containing xanthan, carbopols (934P, 971P, 974P), PVP K30 or PEG 6000 or their binary blends were prepared. The powders were compressed into tablets at a constant compression pressure. Drug release behaviour, swelling and erosion indices and strength of bioadhesion in vitro to a biological membrane were investigated. The interaction between nystatin and polymers was investigated by DSC and FT-IR. Tablets containing the different types of carbopol alone consistently showed an initial burst release of drug, whereas this was not observed for matrices containing xanthan or xanthan-carbopol. The presence of PEG in xanthan-containing formulations induced an increase in dissolution rate; however, in the absence of xanthan the amount of drug release from a PEG matrix was reduced to < 15% over 8 h dissolution. The presence of PVP increased the dissolution rate of nystatin due to the relative hydrophilicity of PVP. The presence of calcium ions induced a more rigid gel in the xanthan matrix as a result of interaction between the polymer and calcium ions. Xanthan can be used in potential mucoadhesive formulations containing nystatin to produce a controlled release of the drug and the outcomes of this work may provide a suitable strategy for matrix selection to provide more efficacious treatment alternatives for candidiasis and other disease processes for significant patient populations.

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