This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments,in situgels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to defense mechanisms of the human eye, extending contact time of drug with the cornea, increasing the penetration through the complex anatomical structure of the eye, and providing controlled release of drugs into the eye tissues, which allows reducing the drug application frequency. The rest of the paper describes recommendedin vitroandin vivostudies to be performed for various ophthalmic drugs forms in order to assess whether the form is acceptable from the perspective of desired properties and patient’s compliance.

In recent years, considerable attention focuses on making sustained release dosage forms also containing solid dispersions. The objective of this study is evaluation of imatinib base (IMA) solid dispersion physicochemical properties which can be useful to controlled release solid dosage formation. The solid dispersions were obtained by kneading method, containing of 10–90% w/w Pluronic F127 (PLU). Drug dissolution test was determined by rotating-disc system method in 0.1 M hydrochloric acid (pH 1.2) and phosphate buffer (pH 6.8). XRD, DSC, FTIR, and SEM observations were performed to evaluate the physical characteristics of solid dispersions. These studies showed that there was no chemical interaction of the IMA with PLU in the solid state and revealed that IMA and PLU form a simple eutectic phase diagram. Our research has shown that the dynamics of the release of imatinib base from solid dispersions with Pluronic F127 depends on the pH of dissolution medium. At pH 1.2, the presence of polymer in solid dispersion causes delaying of drug release due to formation a viscous gel layer, whereas at pH 6.8 significant enhancement of the drug dissolution rate from solid dispersions has been observed compared to pure IMA. The highest improvement was observed in solid dispersions containing 20 and 30% w/w polymer. The present investigation confirmed that the hydrophilic polymer Pluronic F127 could be applied as a suitable matrix to design modified release formulations of imatinib base.

Prepared solid dispersions were applied to a drug with low water solubility to improve its dissolution rate. Fenofibrate (FEN) is a Biopharmaceutical Classification System (BCS) class-II (poorly water-soluble) drug, and its bioavailability is limited by the dissolution rate. The physical state of FEN in solid dispersions with Pluronic F127 (PLU) prepared using the fusion method was assessed using Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and differential scanning calorimetry (DSC). The DSC investigation revealed that FEN and PLU form a simple eutectic system. The DSC, XRPD, and FTIR studies of the investigated solid dispersions revealed no interaction between FEN and PLU. The intrinsic dissolution rate (IDR) of FEN from solid dispersions was significantly increased compared with the pure drug. The enhancement in the intrinsic dissolution rate was approximately 134-fold for solid dispersions containing 30/70 % w/w of FEN/PLU.

Physicochemical Characterization and Dissolution Studies of Solid Dispersions of Clotrimazole with Pluronic F127