Self-Emulsified Nanoemulsion for Vaginal Administration: In Vitro Study of Effect on Lactobacillus acidophilus.

Self-emulsified nanoemulsions (SENs), one of the promising lipid-based drug delivery systems may be used to deliver drugs through vaginal route. Vaginal cavity remains healthy because of the defensive action by its microflora against the pathogenic infections, and any disturbance to this microflora by the delivery systems gives invitation to the infections. In the present study, the growth inhibition and cytotoxic effects of two SENs and their components on L. acidophilus were evaluated. The two SENs showed inhibitory effects on the growth of L. acidophilus in a concentration-dependent manner when tested at the concentration range of 0.1-5.0%. The SEN composed of medium chain mono/di-glyceride had greater inhibitory effect than the one composed of long chain monoglyceride. The study on the effect by the individual lipids with the surfactant Kolliphor® RH40 further confirmed that the growth inhibitory and cytotoxic effects were in the order of Capmul® MCM > Maisine® CC > Miglyol® 810 > Kolliphor® RH40. Both OD600 and CFU counting were used to measure the viability of the culture. The results from the two methods were in good correlation except when there was no growth, suggesting OD600 can be used when there is no complete growth inhibition.

Protection of Protein Drugs by Self-Emulsified Nanoemulsion Against Proteolysis.

The present study aimed to develop a self-emulsified nanoemulsion for salmon calcitonin (sCT) for non-invasive delivery. Hydrophobic ion pairing method was used to form hydrophobic complex of sCT with 4 counter ions (oleate, deoxycholate, docusate and tripolyphosphate). The partition coefficient and dissociation of the complexes in water of various pH were investigated. The complex-loaded nanoemulsions were characterized for droplet size, leakage of sCT from the droplets, and protection of sCT from enzymatic degradation. The results show that all the counter ions could form complexes with sCT with a complexation efficiency about 95% at pH 8.0. The complexes significantly increased the partition coefficient of sCT. The dissociation of the complexes in water was pH-dependent. At pH 6.8 and 7.4, the dissociation was negligible. At pH 1.0, the dissociation was 71%, 8%, 37% and 50% for sCT-polyphosphate, sCT-docusate, sCT-oleate and sCT-deoxycholate, respectively. The developed nanoemulsions had a size in the range of 27-62 nm. The leakage of sCT from the nanodroplets into the aqueous phase depended on the lipophilicity of the counter ions: 60%, 56%, and 24% leakage for sCT-docusate, sCT-oleate and sCT-deoxycholate, respectively. The nanoemulsion protected sCT from enzyme degradation when loaded inside the droplets, but not the leaked sCT.

Formulation and evaluation of bilayered gastroretentable mucoadhesive patch for stomach-specific drug delivery.

The aim of the present work was to develop and evaluate stomach-specific controlled release, gastroretentable mucoadhesive patch of lercanidipine HCl. This drug is essentially soluble in gastric pH range of 1- 4 and have a partition coefficient (log p-value) of 6.1; according to this concept, it has been decided to formulate the gastroretentive bioadhesive patch. The patch system consisted of a drug release rate controlling film, using the combination of Eudragit RSPO and RLPO; mucoadhesive film by using the combination of various hydrophilic polymers. Bilayered patch were made by using the selected batch of two films using the layering method and evaluated for the various parameters like in vitro swelling study, ex vivo mucoadhesive strength. Film was folded into a hard gelatin capsule, evaluated for in vitro drug release in pH 1.2 containing 0.2% (w/v) sodium lauryl sulphate (SLS), and in vivo bioavailability in rabbits. Patches could control the drug release up to 12 h, having mucoadhesion strength in the range of 4.05±0.4 N to 4.52±0.12 N. In vivo bioavailability results indicate that the gastroretentive patch system provides a novel way to retain the drug matrix for the longer period of time in a stomach, enhance drug absorption and thereby offer a promising strategy for gastroretentive mucoadhesive drug delivery for the lercanidipine HCl.