Natural products derived from plants have been used for decades in traditional medicine. Many classes of compounds exist in plants such as saponins, alkaloids, anti-oxidants, etc. Pentacyclic triterpenes are also one of the compounds occurring in plants. In this class Ursolic acid is a well-recognized compound that is available from various sources like seeds as well as fruits and possess many types of activities and is a bright contender for developing novel treatment approaches for treating diseases.

Based on their solubility and permeability, drugs are typically divided into four classes (Classes I–IV) according to the biopharmaceutics classification system (BCS). Of these classes, BCS class II drugs have high permeability and low solubility; not only do these characteristics constitute the rate-limiting step in the formulation of these drugs but the low solubility in water results in low bioavailability. Thus, methods for improving their solubility have been developed using lipid carriers such as liposomes, niosomes, and aquasomes; other approaches include self-micro-emulsifying drug delivery systems (SMEDDS) and self-nano-emulsifying drug delivery systems (SNEDDS). Currently, niosome-based drug delivery systems that utilize nonionic surfactants, drugs, and cholesterol in varying ratios are being widely used to deliver both hydrophilic and lipophilic drugs in addition to several other applications of niosomes.

Nanoemulsions are sub-micron sized emulsions that are undergoing detailed assessment as potential drug carriers for enhancing the delivery of therapeutic agents. These are to date the most developed nanoparticulate systems for the systemic delivery of active pharmaceutical for controlled drug delivery as well as targeting. These are the thermodynamically durable isotropic system, in which two incompatible liquids (water and oil) are blended to form a single homogenous phase by utilizing a required quantity of surfactants to achieve mixing with a droplet diameter approaching roughly in the range of 0.5–100 μm. They find applications in various fields such as cosmetics as well as are adopted in various routes of administration.

Over the past three decades, controlled drug delivery systems have become more developed and play a key role in pharmaceuticals formulations. There are many shortcomings in Traditional or Conventional drug delivery systems like for maintaining desired therapeutic drug plasma concentration there is a need for frequent dosing for particular drugs having shorter half-lives. Furthermore, because of frequent dosing requirement, there is poor patient compliance which causes fluctuation in plasma concentration of the drug. The limitations of conventional drug delivery can be overcome by the development of novel drug delivery systems, of which the controlled drug delivery can maintain constant drug plasma concentration by slowly releasing the drug over an extended period. Developing controlled drug delivery systems can also improve the systemic bioavailability of the drug, thus enhancing the therapeutic efficacy of the drug and better patient compliance. There are many different approaches for such controlled delivery systems such as liposomes, niosomes, ethosomes, phytosomes, microemulsion, and microspheres. Among all the approaches microspheres are more convenient as the drug is slowly released from the polymeric matrix and the polymers used are mostly biodegradable and possess no side effects. Therefore, microspheres can be used in various medicinal departments such as oncology, gynecology, radiology, pulmonary, cardiology, diabetes, and vaccine therapy. This review article focuses on recent different types of microspheres along with their methods of preparation. The microspheres formulated can be later evaluated and characterized by different procedures.

Buccal drug delivery especially refers to the delivery of drugs through the buccal mucosal membrane lining of the oral cavity. For geriatric and pediatric patients who undergo difficulties in swallowing conventional oral solid dosage forms, the buccal film is a better alternative. The buccal film is appropriate for the drugs which experience high first-pass metabolism and is used for enhancing bioavailability with reducing dosing frequency to mouth plasma peak levels, which thus limit side-effects and make it cost-effective. It enhances the efficacy of API in the oral cavity after the contact with less saliva as contrasted to tablets, without chewing and no need for water for administration. This review briefly describes the advantages and limitations of buccal film, an anatomical structure of oral mucosa, highlighting the mechanisms of drug permeation, formulation technologies, methodology in evaluating buccal film, and recent advances of the buccal film as a tool for drug delivery for various treatments.