Solid-State Lipid - Based Lipid Drug Delivery System

In recent time, about 70% of new molecules discovered or under discovery are lipophilic in nature with low aqueous solubility which makes a great challenge for formulation scientists to making these molecules to be have a sufficient aqueous solubility and oral bioavailability. Lipid-based drug delivery system (LBDDS- wide ranging designation for formulations containing a dissolved or suspended drug in lipid excipients) is one of the appropriate approach which gained significant popularity due to their ability to deliver poorly water-soluble drugs with improved solubility and oral bioavailability. Conventional LBDDS, including lipid emulsions, suspensions etc. suffer from various drawbacks limiting their widespread commercialization and use. Therefore, solid-state LBDDS fabricated from conventional LBDDS using different types of solid carriers via various solidification methods eliminated some of the various limitations of conventional LBDDS with great stability. The present review provide overview on the various types of solid state lipid based drug delivery systems, different types of solid carriers use in formulation of solid state lipid based drug delivery system, various solidification techniques for conversion of liquid lipid system to solid dosage form, advantages and some practical limitations of lipid based drug delivery system.

Electroanalysis Applied to Compatibility and Stability Assays of Drugs: Carvedilol Study Case

Carvedilol (CRV) is a non-selective blocker of α and β adrenergic receptors, which has been extensively used for the treatment of hypertension and congestive heart failure. Owing to its poor biopharmaceutical properties, CRV has been incorporated into different types of drug delivery systems and this necessitates the importance of investigating their compatibility and stability. In this sense, we have investigated the applicability of several electroanalytical tools to assess CRV compatibility with lipid excipients. Voltammetric and electrochemical impedance spectroscopy techniques were used to evaluate the redox behavior of CRV and lipid excipients. Results showed that Plurol® isostearic, liquid excipient, and stearic acid presented the greatest anode peak potential variation, and these were considered suitable excipients for CRV formulation. CRV showed the highest stability at room temperature and at 50 °C when mixed with stearic acid (7% w/w). The results also provided evidence that electrochemical methods might be feasible to complement standard stability/compatibility studies related to redox reactions.

Lipid and PLGA Microparticles for Sustained Delivery of Protein and Peptide Drugs

Solid lipid particles have a great potential in sustained drug delivery, the lipid excipients are solid at room temperature with a slow degradation rate. Poly (D, L-lactic-coglycolic acid) (PLGA) has been successfully clinically applied for the sustained delivery of peptide drugs. A recent study showed the advantage of hybrid PLGA-lipid microparticles (MPs) over PLGA MPs for the sustained delivery of peptide drug in vivo. In this paper, we briefly present PLGA MPs, solid lipid MPs and PLGA lipid hybrid MP prepared by the double emulsion method and the spray drying method and discuss the effects of excipients on encapsulation efficiency of protein and peptide drugs in the MPs. The pros and cons of PLGA MPs, solid lipid MPs and PLGA lipid hybrid MP as carriers for sustained delivery of protein and peptide drugs are also discussed.

The Utility of Lipids as Nanocarriers and Suitable Vehicle in Pharmaceutical Drug Delivery

Lipid based excipients have gained popularity recently in the formulation of drugs in order to improve their pharmacokinetic profiles. For drugs belonging to the Biopharmaceutics Classification System (BCS) class II and IV, lipid excipients play vital roles in improving their pharmacokinetics properties. Various nanocarriers viz: Solid lipid nanoparticles, nanostructured lipid carriers, selfnanoemulsifying drug delivery systems (SNEDDS), nanoliposomes and liquid crystal nanoparticles have been employed as delivery systems for such drugs with evident successes. Lipid-based nanotechnology have been used to control the release of drugs and have utility for drug targeting and hence, have been used for the delivery of various anticancer drugs and for colon targeting. Drugs encapsulated in lipids have enhanced stability due to the protection they enjoy in the lipid core of these nanoformulations. However, lipid excipients could be influenced by factors which could affect the physicochemical properties of lipid-based drug delivery systems (LBDDS). These factors include the liquid crystalline phase transition, lipid crystallization and polymorphism amongst others. However, some of the physicochemical properties of lipids made them useful as nanocarriers in the formulation of various nanoformulations. Lipids form vesicles of bilayer which have been used to deliver drugs and are often referred to as liposomes and nanoliposomes. This work aims at reviewing the different classes of lipid excipients used in formulating LBDDS and nanoformulations. Also, some factors that influence the properties of lipids, different polymorphic forms in lipid excipients that made them effective nanocarriers in nano-drug delivery would be discussed. Special considerations in selecting lipid excipients used in formulating various forms of nanoformulations would be discussed.

SOME MULTIFUNCTIONAL LIPID EXCIPIENTS AND THEIR PHARMACEUTICAL APPLICATIONS

This review is generally focussed on lipid-based excipients in solid oral formulations which increase its bioavailability. Several approaches have been used to deliver the drug efficiently in the body, and lipid excipients are one of the promising drug delivery systems which address challenges like solubility and bioavailability of water-soluble drugs. Lipids excipients can be tailored to meet a wide range of product requirements like disease indication, route of administration, stability, toxicity, and efficacy. This review discusses novel lipids like Compritol 888 ATO, Dynasan 114, and Precirol ATO 5 and how these can be employed for devicing efficient drug delivery models and thereby have used in cosmetic and pharmaceutical industries.

A SYSTEMATIC REVIEW ON SELF-MICRO EMULSIFYING DRUG DELIVERY SYSTEMS: A POTENTIAL STRATEGY FOR DRUGS WITH POOR ORAL BIOAVAILABILITY

Currently a marked interest in developing lipid-based formulations to deliver lipophilic compounds. Self-emulsifying system has emerged as a dynamic strategy for delivering poorly water-soluble compounds. These systems can embrace a wide variety of oils, surfactants, and co-solvents. An immediate fine emulsion is obtained on exposure to water/gastro-intestinal fluids. The principal interest is to develop a robust formula for biopharmaceutical challenging drug molecules. Starting with a brief classification system, this review signifies diverse mechanisms concerning lipid-based excipients besides their role in influencing bioavailability, furthermore pertaining to their structured formulation aspects. Consecutive steps are vital in developing lipid-based systems for biopharmaceutical challenging actives. Such a crucial structured development is critical for achieving an optimum formula. Hence lipid excipients are initially scrutinized for their solubility and phase behavior, along with biological effects. Blends are screened by means of simple dilution test and are consequently studied with more advanced biopharmaceutical tests. After discerning of the principle formula, diverse technologies are offered to incorporate the fill-mass either in soft/hard gelatin capsules. There is also feasibility to formulated lipid-system as a solid dosage form. Although such solid technologies are desirable but such should not undermine the biopharmaceutical potential of lipid-formulations.