Introduction

Plants are a common source of medicine globally. Plants have been used for treatments in several countries over the years. They are viewed to be a creation of traditional medicine structures and most commonly Ayurvedic, Unani, Chinese are commonly used (Teschke, 2014). Plants are notable for their therapeutic value and they were found to be the foundation of the care system and recognized for their supernatural power of healing. Herbs have been esteemed as nature's blessing to humankind for its property of mending disease. Herbal medicines comprise herbs, herbal preparations and finished herbal products which contain as dynamic fixings parts of plants or other plant materials saw to have helpful advantages. Herb - herb combination is known to be herbal formulation and has been used in the process over the years, but the scientific evidence of their therapeutic uses is still unknown (Che, Wang, Chow, & Lam, 2013). Herbal formulation it means a dosage form which constitutes two or more herbs in a well-processed form in distinct quantities which is useful to diagnose or to treat the disease of human beings or animals and or it potentially alternate the structure or physiology of human beings or animals (Risberg, Fodstad, & Andersson, 2011).

Many studies have proved the efficiency of herb-herb combinations. In comparison with single drugs, drug combinations have shown a more promising effect in the treatment of disease. This drug combinations conception has been well established in many countries and extraordinary success has been reached (Sharma, 2019). Naturally existing herbal products which are sorted out into a herbal formulation have been shown possible interaction effects in the body. This kind of interaction may occur in the form of enhancement, assistance, restrain, or even antagonism (Kajaria et al., 2012). Herbal formulations have been utilized in the Ayurvedic system to treat several kinds of systemic infectious diseases. Herbal medicine is considered to be a preferred option nowadays, even though several differences exist between herbal medicines and conventional pharmacological treatments (Ames, Dissanayake, & Kasulis, 1994). Nowadays, herbal formulation mediated synthesis of nanoparticles also been used for its efficacy. Nanoparticles incorporated into herbal formulation possess better antibacterial properties and efficiently it is also valuable against the oral pathogens and used in oral medicines (Ezhilarasan, Sokal, & Najimi, 2018).

Specific herbal formulations constituting certain compounds have been considered to be the most productive in treating several disease conditions. Many studies have shown that plants contain a tremendous number of flavonoids, alkaloids, and phenolics. Polyherbal combinations of these plants have shown better efficiency as the majority of the traditional medicinal systems have indicated several complicated diseases can be better managed by drug combinations rather than the effect of a single herb (Mehta, 2019). This methodology will help investigate and estimate the actual therapeutic value of these natural occurring pharmacotherapeutic agents.

A previous study revealed the efficacy and safety of a diabetic topical cream which is made by herbal formulation and found to be potentially more effective and safer than standardized drug silver sulfadiazine (Kalia & Gauttam, 2013). Herbal formulation is also noted for its anti-inflammatory activity. Polyherbal formulation of Allium sativum, Allium cepa, Aloe vera, Ocimum sanctum, Trigonella foenum graecum has shown a critical promising impact in subacute models of rodent paw edema and cotton pellet granuloma separately (Viswanathan, 2011). The formulation indicated better activity than standard indomethacin. Another Polyherbal formulation which is aqueous fraction known as BHUX, has shown significant anti-inflammatory properties through inhibition of enzymes cyclooxygenase-2 and lipoxygenase-15 (Vohra et al., 2008). Herbal formulation namely RIPARE has been noted for its notable antiarthritic property which is formulated by Boswellia serrata, Vitex negundo, Centella Asiatica, Curcuma longa, Euphorbia hirta and Piper nigrum (Tripathi, 2005).

But not all the natural treatments are found to be inherently safe. A herbal formulation may carry risk. So, it is essential to know which herbal remedies do better than side effects and for which condition. Proper preparation of herbal formulation will be effective and safe for consumption. With this background, the review addresses the safety, efficacy, and regulations of herbal formulation.

Preparation of herbal formulation

Herbal medicine can be prepared through various ways, it can be an extract from fresh herbs or in a powder tablet form, or as a pill after shade-drying. (Huie, 2002). Up the medication from new material, the new or dried spices are bubbled in water and utilized as a decoction. In certain facilitates common additives are utilized in the arrangements. For instance, in Arista and Avaleha, jaggery acts as a preservative, but the variation seen is that the Arista is fermented and taken in a liquid form. However, in the case of Avaleha, it is not fermented, and hence, it is taken in a solid form. Likewise, in the cured oil or ghee, the oil and ghee are the common preservatives. In the arrangement of herbal medications, three focuses must be considered in accomplishing great outcomes: quality, amount, and introduction (Frawley & Ranade, 2004). So as to accomplish the above mentioned, talented people in the field are required. These will use specific techniques in the preparation of powder or tablets. These will utilize explicit strategies in the planning of powder or tablets. Such aptitudes are additionally essential in the readiness of Avaleha, Arista, and sedated oil or ghee.

Characterization of herbal preparation

Characterization of the herbal preparation is dependent on few principles: Extracts or preparations of an active principle known, extracts or preparations of active principles unknown, multi or mixed preparation of several drugs or its extracts (Bauer & Tittel, 1996). Characterization of herbal preparations is important for safety assessment, to predict herb to herb interactions, and reduce toxicity.

Efficacy of herbal formulation

Following are a few examples of the herbal formulations employed in traditional medicine:

Dia-beacon is a herbal formulation which contains ingredients Himalayan Gymnena sylvestre, Insulin syzygium cumini, boerhavia diffusa, Tinospora secretagogues is known for its anti-diabetic effect and herbal hills jambu which contains Eugenia jambolana can reduce blood and urine sugar levels (Giovannini, Howes, & Edwards, 2016). Herbal formulations are not only effective in diabetes also in lung diseases. Some herbal formulations used include Bakumond-to, Bufei yishen recipe, Buffei keli, Bushen naqi huoxue, Er chan tang, Kesuning granule, Shenmai injection, Qingning oral liquid (Burzlaff & Tchrakian, 1984). The herbal formulations are effective in chronic pulmonary obstructive diseases, PG201, Joint care B, Articulin F (Kulkarni, Patki, Jog, Gandage, & Patwardhan, 1991) are some of the formulations used in the medication of rheumatoid arthritis. The strong synergism of several constituents presents in the drug improves potency and will be effective in individual constituents.

Safety assessment

As herbs are viewed as plants, they are constantly seen to be characteristic and safe. However, the side effects of herbal formulation have been documented lately. Adverse effects of these herbal formulations have been attributed to drug adulteration and improper preparation. It additionally incorporates the impacts of biologically active constituents present in herbs, contaminants, and herb interactions.

A higher rate of contaminants in the herbal formulation has been accounted for recently. The safety of using certain herbs for treatment is still not well established. Some of the formulations have been known to interact with other drugs and cause irritations. As many of the formulations contain active constituents, they may cause adverse effects through biological fluids (Nortier, 2000).

For instance, ephedra, which contains ephedrine, was generally utilized in conventional Chinese medication for a huge number of years, and afterwards got well known in this nation during the 1990s as a part of weight reduction and vitality improving items. An investigation of contacts to harm control focuses found that contrasted and other generally utilized natural items, ephedra was multiple times bound to prompt a report of a reaction. Along these lines, standardization of herbal formulations is important for safety assessment.

Standardization of herbal formulation

Standardization of herbal formulation is determined to be the way toward endorsing a lot of principles or inalienable attributes, steady boundaries, completely subjective and quantitative qualities that convey a confirmation of value, efficacy, safety, and reproducibility (Kunle, Egharevba, & Ahmadu, 2012). Standardization is the strategy of creating and concurring upon specialized principles. Are mentioned out of experimentation and objective facts by numerous specialists, which would prompt the way toward recommending a lot of attributes displayed by the specific herbal medication. Subsequently, standardization is a tool in the quality control process.

Even though natural medicines have gotten progressively well-known all through the world, one of the disadvantages in its acknowledgement is the absence of a standard quality control profile. The nature of the herbal medication, that is, the profile of the constituents in the last item has suggestions in efficacy and safety (Neeta, 2017). As per WHO, standardization and quality control of herbals is the procedure associated with the physicochemical assessment of unrefined medication covering perspectives, for example, determination and handling of rough material, safety, adequacy and stability evaluation of a completed item, documentation of security and hazard dependent on experience, an arrangement of item data to the buyer and item advancement.

Standardization of herbal formulation includes modifying the readied natural medication to a characterized substance of a constituent or a gathering of substances with realized helpful action by including excipients or by blending herbal medications or herbal drug formulation. Botanical extracts acquired legitimately from crude plant material show considerable variety in an organization, quality, and helpful impacts (Onifade, Olaseinde, & Mokowgu, 2012). Standardized extracts are high-quality extracts which are excellent concentrates which contain reliable degrees of specific compounds which are exposed to thorough quality controls during all phases of the developing, harvesting, and manufacturing procedures. No administrative definition exists for the standardization of dietary enhancements.

Regulations

Several experts have recently suggested a few significant changes to the guideline of herbal formulation that could improve the safety and proper utilization of these items. The most basic component will be to characterize specific guidelines for herbal-based preparations to ensure consistency between studies. Guidelines of food and medications have consistently been unequivocally opposed by industry. Public awareness of the risks of dietary enhancements has expanded as of late, and a greater part of the open backings the possibility of new principles that would require the FDA to audit the safety of new dietary enhancements before their deal; that would give an expanded position to the FDA to expel hazardous items from the market; that would direct promoting claims about the medical advantages of dietary enhancements (Blendon, DesRoches, Benson, Brodie, & Altman, 2001).

Advantages of herbal formulation

Herbal formulations are of a wider therapeutic index. They are also cheap, ubiquitous, and easily available. Herbal formulations also have better acceptance from the patients. It is also evident that the efficacy of the herb combination is more effective than a single herb effect (Ajazuddin & Saraf, 2010).

Disadvantages of herbal formulation

The main disadvantages of ineffectively defined natural medication for herbal medicine which may prompt a few unfavourable impacts and harmfulness. Drug adulteration and improper preparation lead to pharmacodynamic interaction. Numerous herbal products contain undisclosed solutions or over the counter medications and heavy metals. Organic medication can act through a variety of mechanisms to modify the pharmacokinetic profile of economically administered drugs. Drug adulteration may likewise prompt stability issues and poor lipid solubility (Shah & Goyal, 2010).

Conclusion

Ayurvedic or herbal formulation is used for over the world owing it has comparable efficacy, fewer side-effects, better acceptability by people than allopathic drugs. Even though the polyherbal formulation is normally utilized in various parts of the world, the scientific proof is as yet deficient. Many herbal theories are still under in-vivo assessment and have not been assessed by clinical preliminaries. Additionally, safety assessments, for example, toxicological investigations have not performed, poor administrative control and makers' unreliability may likewise influence the nature of the herbal formulations which affects the health of the populations. Prevention of drug adulteration and evacuating control and state-funded instruction or right utilization of herbal formulation is essential. There is a requirement for time to assess polyherbal formulation utilizing logical techniques and scientific reasons, for example, a clinical preliminary, conceivable bioactive compound, and mechanism of action for the future world.

Acknowledgement

The authors would like to acknowledge the host institution to have given support for the opportunity.

Funding Support

The authors declare that we have no funding support for this study.

Conflict of Interest

The authors declare that there is no conflict of interest for this study.