May 17, 2016 - Journal of Pharmacy Research Vol.10 Issue 6 June 2016 ... Available online through ... BCS class III drugs have high solubility but low permeability thus ..... International Journal of Pharm Tech Research 2010; 2: 1681-. 1690.
Sachin M. Kolhe et al. / Journal of Pharmacy Research 2016,10(6),403-409
Research Article ISSN: 0974-6943
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Development and Evaluation of Solid Self Double Emulsifying Drug Delivery System(SSDEDDS) : A Novel Approach to Enhance Bioavailability of BCS Class III Drugs Sachin M. Kolhe1*., Arun T. Patil2., Pradeep P. Bawane1., Jineetkumar B. Gawad1 1 St. John Institute of Pharmacy & Research, Palghar, Maharashtra, India University Department of Pharmaceutical Sciences, Nagpur, Maharashtra, India
2
Received on:21-04-2016; Revised on: 17-05-2016; Accepted on: 15-06-2016 ABSTRACT Background: Even after having a good therapeutic importance few drugs may not be utilize effectively because they may lack either in solubility or permeability. BCS class III drugs have high solubility but low permeability thus bioavailability of these drugs is always low. The present study is based on the development of Self Double Emulsifying Drug Delivery System (SDEDDS) to enhance bioavailability of such drugs. Methods: Four formulation of the w/o emulsions was developed by one step emulsification procedure containing a fixed proportion of ranitidine and different amount of phospholipids. Ranitidine was dissolved in distilled water the pH was adjusted to 6.0±0.5 by a pH meter. Then, the drug aqueous solution was added to the oil phase which consisted with oleic acid, Span 80 and bean phospholipids under moderate magnetic stirring. Hard gelatine capsules (size 00) were manually filled with 890 mg of each formulation (F1–F5), resulting in each capsule containing 40 mg ranitidine. Results: Formulations were evaluated for weight variation, drug content, viscosity, globule size, visual grading, Dissolution & stability. The prepared formulation were complies the test as per the standard. The dissolution study revealed the sustained release of ranitidine from the formulation and enhances in vitro bioavailability. Conclusion: The present studies have clearly demonstrated the potential utility of SDEDDS for formulating ranitidine with sustained release in vitro and improved oral bioavailability in vivo. The SDEDDS readily released the lipid phase to form fine water-in-oil-in-water double emulsions, with a sustained release of ranitidine. KEYWORDS: Self double emulsification, BCS drugs, Solubility, Drug delivery INTRODUCTION: Oral administration is the most favourable route of drug delivery for both patients and manufacturers. Nevertheless, many potential hydrophilic drugs defined as “high solubility low permeability class” or a biopharmaceutical classification system [BCS] class III drug, gastrointestinal permeation is the rate controlling step in the absorption process. Also the drugs which undergo hepatic first pass effect have low bioavailability which can be improved by absorption and transport through lymphatic system. Many approaches such as absorption enhancers, chemical modifications and pharmaceutical means were used to enhance oral bioavailability of those drugs. Among these approaches, water-in-oil-in-water emulsions show great potential for enhancing oral bioavailability of BCS class III drugs, but their industrial application is limited due to instability1,2. *Corresponding author. Sachin M. Kolhe Assistant Professor Department of Pharmaceutics St. John Institute of Pharmacy & Research, Palghar, Maharashtra, India
The most important factor affecting the oral absorption of a drug, besides dissolution, is the permeability of the drug across the gastrointestinal lining. Improving permeability may, therefore, potentially improve the bioavailability of a drug. Transport of hydrophilic drugs across the intestinal epithelium is confined mainly to Para cellular pathways. However, the limited surface area and the tight junctions present between the adjacent cells restrict the transport of the drugs and are responsible for the low bioavailability of hydrophilic drugs across the Para cellular route3. The small oil globules are absorbed through lymphatic system their by bypasses portal circulation and hepatic first pass effect. Role of lymphatic transport pathway in absorption of fats: Lymph vessels called lacteals are present in the lining of the gastrointestinal tract, predominantly in the small intestine. While most other nutrients absorbed by the small intestine are passed on to the portal venous system to drain via the portal vein into the liver for processing, fats (lipids) are passed on to the lymphatic system to be transported to the blood circulation via the thoracic duct.
Journal of Pharmacy Research Vol.10 Issue 6 June 2016
403-409
Sachin M. Kolhe et al. / Journal of Pharmacy Research 2016,10(6),403-409 Transport of lipids into the circulation is also different from what occurs with sugars and amino acids. Instead of being absorbed directly into capillary blood, chylomicrons are transported first into the lymphatic vessel that penetrates into each villus. Chylomicronrich lymph then drains into the system lymphatic system, which rapidly flows into blood. Blood-borne chylomicrons are rapidly disassembled and their constituent lipids utilized throughout the body. When large numbers of chylomicrons are being absorbed, the lymph draining from the small intestine appears milky and the lymphatics are easy to see. In the image below, of abdominal contents from a coyote, the fine white lines (arrows) are intestinal lymphatics packed with chylomicrons. That lymph passes through mesenteric lymph nodes (LN) and then into larger lymphatics4-7. Preparation of Double emulsions The w/o/w double emulsions are prepared by a modified two-step emulsification method. First step involves the preparation of primary emulsions where w/o emulsion is prepared using lipophilic surfactant. In second step primary emulsion is mixed with hydrophilic surfactant to form w/o/w emulsion. Self-Emulsifying Drug Delivery System (SEDDS) SEDDS are solid dosage form with a unique property that is they are able to self-emulsify rapidly into fine O/W emulsion in the gastrointestinal fluids, under gentle agitation provided by the gastrointestinal tract. This fine O/W emulsion results in small droplets of oil dispersed in the gastrointestinal fluids that provide a large interfacial area enhancing the activity and minimizing the irritation due to contact of drug in the gut wall. Self-Emulsifying System (SES) can be formulated with little energy input and the shelf life is longer than conventional emulsions8-17. Therefore, an SES can be an efficient vehicle for class II to IV molecules of the Biopharmaceutical Classification System (BCS) drugs. Self-double-emulsifying drug delivery system (SDEDDS) SDEDDS can spontaneously emulsify to water-in-oil-in-water (w/o/ w) double emulsions in the mixed aqueous gastrointestinal environment, with drugs encapsulated in the internal water phase of the double emulsions12.
Oil
Lipophilic emulsifier
W/O emulsion
Intestinal lumen
Hydrophilic emulsifier (Capsule)
Water
W/O/W emulsion
Figure 1: Process for preparation of SDEDDS DRUG PROFILE For the drugs to be formulated as SSDEDDS, it must be of BCS class III having low bioavailability. Ranitidine is one of such kind of drug which has low bioavailability (50-60%) and highly soluble in water. It is most widely used drug for the treatment of hyperacidity and peptic ulcer related problems. It is given orally and has first pass effect (Table 1). Table 1: Drug Profile Molecular formula
C13H22N4O3S . Hcl
Molecular weight pH in aqueous solution Solubility
350.87 4.5-6.0 Freely soluble in water, methanol and Insoluble in oils. 229 nm and 313 nm Zollinger-Ellison syndrome, GERD, gastric ulcer, duodenal ulcer, erosive esophagitis
Absorbance Uses
Ternary phase diagram Pseudo-ternary phase diagram was constructed to identify the selfdouble-emulsifying regions for the selected vehicle (w/o primary emulsion and Tween 80). As shown in figure area under curve represents the double emulsion region. It is important to determine this area in order to ensure successful conversation of pidotimodSDEDDS to double emulsion by dilution with distilled water. Combined with surfactant (