## 3 Results and Discussion
### Dissolution Test Results and Korsmeyer-Peppas Release Kinetics
The presence of the excipients reported herein in these developed formulations may lead to more complex interactions between drug molecules and the polymer matrix, contributing to anomalous diffusion. In contrast, formulation F2 follows a Super Case II release mechanism (n > 0.89), which is commonly associated with systems where polymer relaxation dominates. The release rate is primarily controlled by the polymer matrix, which swells significantly and leads to a constant release rate, a mechanism previously described in systems with highly swelling polymers [59]. In Figure 6b the % MLT release vs. time from the F1, F5, and F9 formulations and Circadian(r) is depicted. These formulations are comprised of the same polymeric material, neat PLA, the latter two, however, containing half the quantity of neat PLA (33 mg), compared to F1 (67 mg). F5 shows the highest MLT % release (49.79%), at t = 2 h, and 100% release, at t = 5 h, faster than from F1, F9, and Circadian(r). Notably, the lowest % release of MLT (36.3%), at t = 2 h, is shown from F9. The low % release from F9 is possibly due to the 6-fold higher quantity of MCC (119 mg) in this formulation compared to the 20 mg MCC present in F1 and F5. This leads to increased gel formation in the case of F9, when MCC comes in contact with the aqueous medium, resulting in MLT release retardation [60, 61]. According to MLT release kinetics obtained via the Korsmeyer-Peppas equation (Table 3), it is concluded that, in the case of the F1, F5, and F9 formulations, a non  
Figure 7: Schematic representation of H-bond formation between MLT C5-OMe and sorbitol OHs. Fickian/anomalous diffusion release mechanism (0.45 < n < 0.89) is followed, i.e., a combination of simple diffusion and Case II transport of abnormal diffusion. Figure 6c illustrates the % MLT release vs. time from F2, F6, F10, and Circadian\({}^{\circledR}\). These formulations are comprised of the same polymeric material, PLA-sorbitol, differing, however, in the relative amounts of this excipient, and in the relative amounts of the other formulants they are comprised of. Formulation F2 shows the highest MLT % release (81.3%), at t = 2 h, followed by a rapid release of 100%, achieved at t = 4 h, which is much faster than that from Circadian\({}^{\circledR}\) and the formulations F6 and F10. The lowest % release of MLT, at t = 2 h (44.9%) and until 100% release is achieved at t = 8 h, is shown in the case of F6, where the quantity of the gel forming HPMC is relatively high, and that of the aqueous dissolution enhancer, lactose, is low (8 mg). Lactose is a water-soluble filler and diluent; upon contact with dissolution media, it dissolves rapidly, creating pores within the tablet matrix. This sustained release can be attributed to the use of the hydrophilic polymer (HPMC) that acts as a release retarding agent [62; 63]. However, F6 follows a similar % MLT release profile, at t \(\geq\) 1 h, to Circadian\({}^{\circledR}\). F10 shows an average % MLT release pattern, when compared with the F2 and F10 formulations; indicatively at t = 2 h, the release is 59.93% (Figure 6c). In this formulation the quantity of the gel forming MCC formulant is higher than in the other two formulations. According to the MLT release kinetics obtained via the Korsmeyer-Peppas equation (Table 3), it is concluded, that from the F2, a Super Case II MLT release mechanism is followed, whilst from the F6 and F10 formulations, the non-Fickian/anomalous diffusion release mechanism (0.45 < n < 0.89)--i.e., a combination of simple diffusion and Case II anomalous diffusion transport release mechanism--is predominant. Figure 6d shows the % MLT release vs. time from the F3, F7, F11 formulations, and Circadian\({}^{\circledR}\). These formulations are comprised of the same polymeric material, PLA-glycerol, differing in the relative amounts of this particular excipient and also in the relative amounts of the other formulants of which they consist.