This study investigated optimizing the formulation parameters for encapsulation of a model mucinolytic enzyme, -chymotrypsin (-CH), within a novel polymer; poly(ethylene glycol)-co-poly(glycerol adipate-co--pentadecalactone), PEG-co-(PGA-co-PDL) which were then applied to the formulation of DNase I. -CH or DNase I loaded microparticles were prepared via spray drying from double emulsion (w1/o/w2) utilizing chloroform (CHF) as the organic solvent, L-leucine as a dispersibility enhancer and an internal aqueous phase (w1) containing PEG4500 or Pluronic® F-68 (PLF68). -CH released from microparticles was investigated for bioactivity using the azocasein assay and the mucinolytic activity was assessed utilizing the degradation of mucin suspension assay. The chemical structure of PEG-co-(PGA-co-PDL) was characterized by 1H NMR and FT-IR with both analyses confirming PEG incorporated into the polymer backbone, and any unreacted units removed. Optimum formulation -CH-CHF/PLF68, 1% produced the highest bioactivity, enzyme encapsulation (20.083.91%), loading (22.314.34 µg/mg), FPF (fine particle fraction) (37.630.97%); FPD (fine particle dose) (179.889.43 µg), MMAD (mass median aerodynamic diameter) (2.951.61 µm), and the mucinolytic activity was equal to the native non-encapsulated enzyme up to 5 h. DNase I-CHF/PLF68, 1% resulted in enzyme encapsulation (17.443.11%), loading (19.313.27 µg/mg) and activity (81.92.7%). The results indicate PEG-co-(PGA-co-PDL) can be considered as a potential biodegradable polymer carrier for dry powder inhalation of macromolecules for treatment of local pulmonary diseases.

Phytochemical investigation of the aerial parts of Sanchezia nobilis Hook. family Acanthaceae has yielded matsutake alcohol (1-octen-3-ol) (1) and four matsutake alcohol glycosides identified as 3-O--glucopyranosyl-1-octen-3-ol (2), 3-O--glucopyranosyl-(16)--glucopyranosyl-1-octen-3-ol (3), 3-O--arabino-pyranosyl-(16)--glucopyran-osyl-1-octen-3-ol (4), and 3-O--arabino-pyranosyl-(16)--glucopyranosyl-(16)--glucopyranosyl-1-octen-3-ol (5). The structures of the isolated compounds were assigned on the basis of different techniques of NMR spectral analysis. Compounds 1–4 have been isolated here for the first time from the family Acanthaceae, while compound 5 is isolated here for the first time from a natural source.

Microemulsions are promising drug delivery systems for ocular delivery of drugs, especially water insoluble drugs such as diclofenac in its acid undissociated form. Microemulsions are characterized with high surfactant content (> 10% w/w) in order to lower the interfacial tension which facilitates dispersion process during the preparation of microemulsion and provides a flexible film around the droplets. However, there are a few researches that have studied the possible irritation effect of microemulsion on the eye. Therefore, evaluation of the ocular irritancy is an important requirement in the development of ocular delivery vehicles such as microemulsions. Draize test using rabbits was used for evaluation of the ocular irritation potential of the prepared microemulsions. The efficacy of the anti-inflammatory action of the formulation showing the least Draize score was then evaluated using 3% croton oil in 2-ethoxyethanol to induce corneal inflammation in rabbits. Results showed that the tested formulations, M5 and M6, were non irritant (NI) where they showed a Draize score of 8 and 14 respectively. When M5 was studied for its anti-inflammatory action and compared with marketed eye drops, Epifenac, it showed a significantly shorter recovery time compared to Epifenac eye drops.

Conventional dosage forms such as eye drops are the most used dosage form by ocular route, in spite of their low bioavailability and the pulsed release of the drug where it is expected that direct application of the drug to the eye will give maximum response; however after instillation of an eye drop, about 70% of the administered volume can be seen to be lost by different factors. For this reason new ocular drug delivery vehicles have been developed in order to minimize the amount of the drug lost from the eye and at the same time provide maximum response with reduced frequency of administration. Among such delivery systems are microemulsions. Microemulsions are a promising dosage form for ophthalmic application because their industrial production and sterilization are relatively simple and inexpensive; they have good thermodynamic stability and inherently provide the capacity to make soluble lipophilic drugs. At the same time, the in vivo results and preliminary studies on healthy volunteers have shown a delayed effect and an increase in the bioavailability of the drug. The proposed mechanism is based on the adsorption of the nanodroplets, representing the internal phase of the microemulsion and acting as drug reservoir, on the cornea and thus increasing the time in which the drug is available for absorption. This review will discuss the important characteristics of ocular delivery systems, factors that reduce drug availability to the eye and methods to improve ocular bioavailability. It will also focus on microemulsions, their preparation methods, their components and their applications as drug carrier for ocular use.